Hi, I think is major changes between 12.02 and 12.2 and because this the automatic update isn't working. If you want to update, make a backup and start the update manually. At least in that way I made it. Because I found few strange things in the LE 12.2, I switched to 12.2 nightly builds (works pretty well).
Also you should read this too: LE 12.2 info
I have almost zero experience with Linux.
Hi, that's a good opportunity to learn a bit. 
If there's a step-by-step tutorial available, directions to it would be great.
You should take a look here: Libreelec + NextPVR
Between the 12.02 and 12.2 stable version, were a lot of nightly images. If you want and have time, you could test few of them, maybe could find which was the first with that wifi issue. That could help the devs to find the root cause. If you are interested, could take a look here: LE 12.0 Nightly
and I bet it’s tripped up plenty of others too.
Glad you managed to make that RPi4 - CRT setup. Your config is a rare specialty, I don't think to be to many people to use ancient CRT displays in this days (20 years ago I seen and repaired enough of those). And the fact that the video source is 4:3 format doesn't means it's needs a same display, I think even a cheap HD ready LCD display could provide a better quality than an old CRT (even it's a Sony trinitron).
Hi, Always try to start the TV first, than the LE/Kodi device. Some old TV's doesn't provide EDID (display data) when are in stand-by and the LE don't know what it's the correct resolution. If it's an old TV, the native resolution can be different than the 1080 (full HD), try to find the native resolution (ex. try with a PC or switching the resolution in the LE settings - when you got the best sharp picture). Example I have an old LG with 1366 x 768 at 60Hz.
So the error is in deleting and adding items in the database.
Do you use the Kodi built-in database (SQLite), the Kodi database addon (MariaDB) or a database installed somewhere else? You should try to change it, to see if the bug remain the same. If you use Kodi on multiple device, the joint database it's an advantage, maybe you should think to install to your NAS server (if it's always on). Kodi-MySQL
First, new clean OS - when i used hdparm command, drives stopped and stayed in this state.
In that case probably some kind of addon, settings, present in your original LE setup, doesn't let the HDD to stay in sleep. You should continue to add your stuffs, and check the HDD. Isn't impossible to have at the end a setup without that issue. Sometimes after upgrade or updates can remain some "old" settings or files that can lead to strange effects.
Where and how should I enter those above numbers during TVHE configuration?
TVHeadend server web interface, PC or laptop: open a web browser and navigate to http://<ip-address>:9981 (replace the <ip-address> with the ip address of your LibreELEC device). Use google to find more about "TVHeadend server setup" or "TVHeadend web interface". The setup isn't very simple, needs a bit of "thinking", but after all, need to be done once, then you can forget it (at least till your provider will modify something...).
Hi, first I would to try a fresh, minimal install on a spare SDcard. With default skin and without any addons. And if the drives going well to sleep, would try to add modifications, step by step. That could work if the drive sleep issue coming from an additional app.
Hi, I own 3 Astromedia Tuners, one (the older) with Panasonic chip, and two with the Sony (CXD2837ER) and working well with LE. One of the Sony version a bought defective, I managed to repair it (I'm working in the electronical industry). So, these devices are cheep... but the quallity sometimes... cheep. Maybe that it's the case with your device too. Try to verify the antenna signal quallity (ex. with a TV). Try (if you didn't tried yet) to check with another OS (Linux, Win), with another program, and if isn't working, probably it's defective.
I counted at least 30 people, and those are just the ones that spoke up about it.
I'm wondering, beside that number is really small comparing to all RPi LibreElec users, how many of them doesn't using their devices, waiting for a solution, and how many switched to alternative methods (LAN cable, USB-wifi dongle with better antenna) and using it without issues. 
BTW, did you tried with the same wifi source every times? Maybe it's some kind of settings or something at your router what with the iwd in the RPi lead to that "bug".
Girlfriend doesn't know how to SSH. Simple option is to just have a button.
Either way, I'd still like this feature even if it doesn't work when it black screens.
Don't forget, the RPi isn't a PC. Doesn't have the same (hardware) reset button. So in the case of the RPi, some kind of the software should "process" the signal from a GPIO in. I didn't know how is your RPi, when you want to reboot it, only the Kodi or the media player is frozen or the entire system... But if the whole system halted, isn't able to process any commands (including the one from GPIO3).
If don't want to use SSH, you should try a Kodi remote app like the "Kore" to check if the RPi can to reboot yourself. If isn't working, no other way, you need to use a button to interrupt the power...
Just got a random black screen, button worked to power it down, but still no reboot.
Did you tried to press again the button after shut down? The original purpose should be to shut down and power up too.
Randomly it will stop playing or get hung up at a black screen.
That means probably the system is frozen, so a software reboot solution, like reading a GPIO (button) status or SSH command, probably can't be used. As the RPi doesn't have hardware reset button option, remains only the "power them off and back on" as a solution. If you want to use a button, could try a button with "normally closed" contact to interrupt the power of the non working RPi when is pressed...
I've set up some screens in the reception at my office with slideshows that use a 90' rotation.
RPiOS and an image viewer for slideshows? Or a slideshow screensaver? Don't know if for that you should use Kodi...
Hi, the existent channels working? Probably is a TVHeadend server addon or a tuner driver issue. In the TVH server addon settings, at versions, could you change to an older version (if listed any, disable the auto-update first)? Or maybe you could update to a newer 12.2 nightly version, small chance, but if in the kernel-driver, maybe already fixed.
If you have time and a spare SDcard, you can try even the latest LE13 nightly build too. Just a quick test, with basic settings, THV server, and to see if it's working or not.
trying to discover the root of the "subtitle issue"
Hi, what kind of subtitle issue did you experienced with TVH4.3? I'm switched to TVH4.3 some times ago, struggled a bit with subtitle settings, resolved finally in the Kodi settings (player/language).
And WiFi automatically connected to your AP after that?
Exactly, and I tried again that (latest LE12 nightly on the card) still without wifi issue. And because last week I wanted to try the LE13 nightly, I still have it on a spare card. Using the LE13, I tried twice the same thing with power off then on, and no wifi issue. In the past, I had wifi issues: started the TV (the RPi it's always on), the LE asked for wifi password but didn't accepted or sometimes just started without wifi connected, after a reboot started without issue. Could be the same issue?
3B or 3B+? 3B uses a different WiFi chip (Broadcom BCM43438) than RPi3B+/RPi4 (both Cypress CYW43455). So that would also point to a driver-related issue.
Maybe yes, or maybe it's already fixed in the nightly builds whatever it was. If you don't have a spare card, you could make an LE backup, then update to latest LE12 nightly (because you can go back to LE12 stable if you will want it, the downgrade from LE13 not guaranteed) and try it...
Nope, definitely not the antenna, or it wouldn't be so reproducible. It's only after cold boot. Never after reboot. 100%. RPi is next to the AP.
If the RPi is next to your AP and you have any chance to use cable instead wifi, don't hesitate, change it. Far better speed, without issues. I have 3 RPi's with LE installed and at only one had wifi problems (no way to use cable in that place). The another two with cable connetion to my router, never had any network issue in the last years.
As I'm using almost same config, RPi3B, wifi (mod. for external antenna), and latest LE12 nightly. So I pulled of the power and connected back after few seconds. The LE booted without any wifi issue...
