TV picture is larger than the screen

Gemini system with internet:  Was giving trouble, and then it became unable to complete booting after a couple of months.  Got a replacement, and after a few days of working, suddenly the TV picture is now larger then the screen, on all programs including the Home screen.  Not a huge change, but enough larger that the closed captions are partially off screen and make no sense.  There are no settings about screen size.  Reboot is no help, simply stuck there now.  Does that just need replacement again?  It was OK for a couple of days.   I tried resetting the TV to resize screen to match signal, but no change.    It is on a 6 year old 55" Sony Bravia, that has never given any trouble and works fine with a Firestick.

Another problem.  I have two Directv TV sets, and  BOTH periodically (maybe every 4 hours or a bit more) the untouched system always simply resets the TV Input from HTMI 4 to TV (for an external antenna, but there is not one).  I am guessing it is related to the remote not being touched in all that time.  I can understand wanting to turn itself off, but NOT the Input change.  Also simply turning the remote OFF also does the same thing (changes Input to TV, every time) which has to be  reset when next turned on.  How can that be stopped.

Also, how  can it be made possible for the two TV sets to have individual recorded libaries, separate and independent for each user Account?  It has the multiple user accounts, how can they be used in the recorded library?