OK, you've all seen this post a 1000 times, and I need some help and nothing I've read works.
New install. No addons installed yet except those needed for live TV/PVR.
Newest version of Libreelec on new Pi4B w 2gb memory with newest eproms flashed. Tuner is Hauppage WinTV Dual Tuner.
NETWORK: I have a fast wired cable connection (or fast enough, package is 300down, 20up) with speed tests showing 180mb/s download, with the Pi set to a static IP. Google Nest pucks, 3 in a condo of 1600sqft, with fast connection from the same hub at my computer and TV which can all stream 4K.
Created an advancedsettings.html file as follows:
LibreELECBR:~/.kodi/userdata
<advancedsettings>
<cache>
<network>
<buffermode>1</buffermode>
<memorysize>209715200</memorysize>
<readfactor>20</readfactor>
</network>
</cache>
</advancedsettings>
Server and client are both set up on the same Raspberry Pi. The front end is the TV Headend HTSP client and the back end is the TV Headend Server, both downloaded from the Libreelec repository. I have about a dozen channels in the Toronto area, I am a mile from the CN Tower with a good antenna.
All addons are up to date.
I've set frame rate of the player to 59.94 same as LG TV. Resolution 1920 x 1080.
Adjust refresh display rate = ALWAYS
Sync playback to display = OFF
Please take some time to help a new user.