Unable to permanently set fixed screen resolution with Xubuntu and large TV

[JimS]

I recently updated my MythTV box from Ubuntu 14.04, Mythtv 0.27 (which was working fine, BTW) to Xubuntu 22.04 with mythtv 32. The system is working ok but there is one big issue with the OS. It automatically sets the resolution to a high value and the display only takes up the upper left hand 1/4 of the screen. I can adjust the display to 1960 x 1080 which gives a good display but on reboot it reverts to the high resolution. Have had numerous suggestions of what to change but nothing has worked.

You can see my other attempts here:

https://ubuntuforums.org/showthread.php?t=2489667

Hoping to find a solution...