Yeap, missed a step. I when back and did the:
Go to the CONFIGURATION > CHANNEL/EPG > CHANNELS tab
Then reran the EPG internal grabbers and it worked.
Thank you @jfabernathy for confirming that sd4tvh works on the new RPi4. That is good news. 
Thank you @jfabernathy for confirming that sd4tvh works on the new RPi4. That is good news.
The RPI4 4GB with LibreELEC 9.2.3 and the HDHomerun tuner make a pretty good PVR and LiveTV with pause solution now that SchedulesDirect data can be used.
Okay, now I need some help. My RPi4 with TVH and sd4TVH started freezing with spinning circles over the Kodi screen and became unusable. So I thought I'd check if it was RPi4 related.
So I took a RPI3B+ and put LE 9.2.3 on it and added TVH server and client. Got that working and then moved on to sd5tvh. I'm not sure if I need to change the TVH server setting for XMLTV source type?
Without changing anything in the server configure I set everything up using the web interface. when I enable the sd4tvh addon in the epg grabbers I get the following errors:
2020-07-03 12:07:02.774 xmltv: /storage/.kodi/addons/script.module.sd4tvh/bin/tv_grab_sd4tvh: grab /storage/.kodi/addons/script.module.sd4tvh/bin/tv_grab_sd4tvh
2020-07-03 12:07:02.778 spawn: Executing "/storage/.kodi/addons/script.module.sd4tvh/bin/tv_grab_sd4tvh"
2020-07-03 12:07:36.424 spawn: cat: can't open 'xmltv.xml': No such file or directory
2020-07-03 12:07:36.426 xmltv: /storage/.kodi/addons/script.module.sd4tvh/bin/tv_grab_sd4tvh: no output detected
2020-07-03 12:07:36.426 xmltv: /storage/.kodi/addons/script.module.sd4tvh/bin/tv_grab_sd4tvh: grab returned no dataAm I support to put the xmltv.xml file somewhere or tell TVH server where it is?
Am I supposed to put the xmltv.xml file somewhere or tell TVH server where it is?
Not that I'm aware of. If I recall correctly this is the message text seen from the first time running the "Re-run Internal EPG Grabbers".
The process to set up sd4tvh is a tad confusing because it requires running the "Re-run Internal EPG Grabbers" two times.
Perhaps you missed a step?
After the first run, go again to the "Configuration -> Channel / EPG -> Channels" tab and this time set an "EPG source" for each channel. On a subsequent run of "Re-run Internal EPG Grabbers" the show listings should be loaded.
EDIT:
You might ssh to your kodi box and check ~/.kodi/userdata/addon_data/script.module.sd4tvh/sd4tvh.log for more details.
I didn't see any obvious issue in the log file and I have re-run multiple times with the same missing xmltv.xml file error.
So I used the Kodi interface and worked with sd4tvh addon and looked at the selected and deselected channels not changing anything but when I exited and re-ran the internal grabbers this time I got the list of channels and then I could add them in to the EPG source for each station. After editing I could then re-run the grabber to get all of the EPG for 3 days.
Since I've done this before, I'm not sure what got this system confused, but it's working now.
So the goal of all this is to see if the lock up of Kodi happens on the RP3B+ like it did on the RPi4
It's possible that the step where you "worked with sd4tvh addon and looked at the selected and deselected channels not changing anything" did make a difference.
It seems that the filter.cfg file is written or re-written (I checked the timestamps) when entering the "Add & Remove Channels from Lineup" option. Depending on the settings this might make the difference between sd4tvh working or not.
I think I always go into this last sd4tvh menu option. More testing is needed to see if this step is always required (at least with the current code in 0.3.4).
So I have it working but a question arises. What happens if I leave the Over-the-air: PSIP: ATSC grabber enabled along with the sd4tvh internal grabber?
Does it create problems or does it leave the channels where I selected sd4tvh in the EPG Source alone?
When I had multiple grabbers enabled at the same time it seemed to me that the data from the last one run would be reflected in the listings. This was helpful if the OTA ATSC grabber listings were more accurate last minute. However, more often than not I found that the ATSC grabber listings were not as accurate as Schedules Direct. In the end I disabled all other EPG grabbers and left only the sd4tvh one enabled.
I've been running tvheadend with sd4tvh on a Raspberry Pi 3B since November, 2017 and the system has been very reliable for me. The Kodi frontend crashes from time to time, but for the most part the tvheadend backend server continues recording shows. On very rare occasions I have discovered that somehow the whole OS crashes in a bad way, but I've also had these rare hangs in MythTV (my main PVR in the house) and with my normal Kubuntu desktop, so I don't think that any one of these is more unreliable than any other (not like the days when I used to run, or should I say keep rebooting Windows 98 
Thanks, BTW, I feel that for maximum stability, no matter which hardware you use or which backend, TVH or MythTV, you need a separate backend system. My current Mythtv backend is a Core i7 that's at least 8 years old. Since it's running on Ubuntu 18.04 Server it's stable and only needs rebooting when I do maintenance or upgrade some software- no GUI desktop software to chash or need work. Using RPi's or FireTV 4K sticks, or Shield TV's as frontend allows me to do all my streaming an liveTV from the same unit. I run Mythtv-frontend, Kodi, Netflix, and Prime Video all on the same frontend.
I think I know the answer to this, but wanted to confirm. If I change the zipcode in sd4tvh and re-select channels for the data I'm getting from SD, does it affect other setups like my home Mythtv that also uses SD for it's schedule data with my home zipcode.
This in important because if I have my RPi4 with LibreELEC, tvh, kodi, and sd4tvh setup to a different zipcode because I'm traveling and using the RPi4 in my RV I don't want that to screw up my home setup with my home zipcode. I know tv_grab_zz_sdjson_sqlite that I use with Mythtv can support multiple setups with multiple zipcodes. Not sure about sd4tvh.
If I change the zipcode in sd4tvh and re-select channels for the data I'm getting from SD, does it affect other setups like my home Mythtv
Adding a lineup (with a different zip code) to SD should not adversely affect other SD clients. The other SD clients might see one more lineup when they query SD, but that shouldn't be a big hit on performance.
However deleting a lineup that is used by another SD client would definitely have an adverse impact.
Adding a lineup (with a different zip code) to SD should not adversely affect other SD clients. The other SD clients might see one more lineup when they query SD, but that shouldn't be a big hit on performance.
However deleting a lineup that is used by another SD client would definitely have an adverse impact.
Okay, first test of changing zipcode when on the road didn't work. Maybe you can figure out where I went wrong.
I tried this first with the exact same setup I used at home with Zipcode #1. After that didn't work as expected I did a fresh install of LE 9.2.3 and got the same results.
I deleted all the channel, and tags then ran the Wizard again for a new mapping of all the channels I could receive. Then I added Zipcode #2 and when through the setup for the channels I could actually receive and removed those that I could not see. Next I re-ran the Internal Grabbers and tried to change the EPG source. (I've actually rerun the Internal grabbers multiple times, same results) My only choices were all from Zipcode #1 and none from Zipcode #2. So I'm not sure what went wrong?
Any ideas?
BTW, I'm not a fan of having to re-run the wizard because it forgets my existing recordings made from an old location. I've used LE and TVH before only using OTA EPG but I still had issues getting new channels when I moved to a new location. I just couldn't find the new channels without Rerunning the wizard.
When you were at your new physical location, did you remember to update the tvh backend?
More specifically, did you go to Configuration -> DVB Inputs -> Networks, click on the ATSC-T Network entry and then choose Force Scan?
This would update the TV channels, but has the potential to create multiple entries for a single broadcaster (e.g., ABC).
The method I would suggest would be to first remove the existing channels, services, muxes, etc., prior to scanning for the channels at the new location and then setting up sd4tvh. I've done this before and I have not lost access to prior recordings. By doing this I have not needed to re-run the setup wizard.
To remove prior entries I suggest under Configuration -> General -> Base changing the User interface level from Advanced to Expert (remember to Save the settings changes).
Then Delete the applicable channels, services, muxes, etc. under the following menu areas:
Note that I'm not an expert on Tvheadend so there might be an easier way to do this. There might also be steps I've missed. All I can say is that using steps similar to the above I have been able to remove and add IPTV channels without loosing normal access to prior recordings. These prior recordings remain in the Tvheadend database and are accessible from the TV recordings menu.
'Hope that helps.
I appreciate your ideas to try. However, what bothers me most is my second effort was a fresh install of LE on a SD card and completely new install of everything including sd4tvh. This is odd that I don't see my new stations as EPG sources. I only see EPG sources for the other zipcode at home.
I did another test. I put my mythtv31 setup on the RPi4 and setup XMLTV using tv_grab_zz_sdjson_sqlite and used the new zipcode and got listings for all my new stations for 21 days. So the zipcode is valid in SD, I just can't make the connection using sd4tvh and TVH.
Jim A
I recall that you mentioned earlier issues with getting the channels from the listings to show up in Tvh. I'll investigate to see if I can replicate the problem.
The home zipcode is 27592 and the new away zipcode is 27030. I don't think there are any overlapping channel numbers. If I use the Kodi addon figure and open functions on sd4tvh It shows me both zipcodes and I picked 27030, and I shows all the right channels there. I can select and exclude the ones I want, which are only 8 channels in this remote location. However after I force the first EPG internal grabber rerun The Configuration -> Channel /EPG -> EPG Grabber channels shows all the channels for that zipcode and not the 8 I included in my selection using the Kodi addon sd4tvh config. Those same channels are the ones I see when I try to assign EPG sources on the Channels tab.
The following tests were performed with LE 8.2.5 as there are firmware issues with 9.2.3 on RPi3 (to be fixed in 9.2.4). Following is my testing and a suggestion to try.
The sd4tvh Configure Settings and Options -> Options I'm using for this test are:
I discovered one anomaly while setting up the sd4tvh listings in that the TV -> Guide displays the old data from Over-The-Air PSIP: ATSC Grabber even after I configure sd4tvh. That is until I reboot. This might be a display issue bug in LE 8.2.5.
More specifically for the testing I disable all the other EPG Grabber Modules, enable sd4tvh, run the internal EPG grabbers, select the EPG source channel/XMLTVID for each channel, then re-run the internal grabbers. After doing this I expect to see the updated SD listings; however what I see is the old ATSC EIT listings. That is until I reboot, at which point the SD listings magically appear in the TV -> Guide.
Note that I have not even looked at the sd4tvh menus for Adding or Removing Schedules Direct Provide Lineups, or Adding & Removing Channels from Lineup. I have only set items in the sd4tvh Configure Settings and Options menu.
The sd4tvh settings Options I'm using at this point are:
Note that I previously added 2 lineups to my SD account, and the ATSC stuff was in the first lineup. When I add another set of channels (IPTV for my test), I do not see the 2nd lineup listing of channels in the drop-down list of EPG source channels/XMLTVIDs.
To get the 2nd lineup channels to appear I had to do the following:
Set sd4tvh Configure Settings and Options as:
Then re-run the internal grabbers.
Note that this put all of the channels into the drop-down EPG source list from the 2nd lineup.
To shorten this list I think should have first used the sd4tvh Add & Remove Channels from Lineup menu entry.
SUGGESTION:
Can you try setting sd4tvh Configure Settings and Options as:
Optionally limit channels with sd4thv Add & Remove Channels from Lineup.
And Re-run the internal grabbers.
Then see if you can then select the 2nd lineup channels/XMLTVIDs for each channel EPG source?
