U-verse TV Equipment

I’m trying to help my aunt to setup her UVERSE receiver, but after completing the initial setup screen with the gear icon, the process proceeds to the second screen with two gear icons before shutting down with the error message consisting of a red ‘X’ and the numeral 3. I’ve tried this process twic

Is there any way to turn only my TV on and off with the S20-S1A remote, as there is with the S-10 remote?

I have had Uverse for approximately 12 years. I have one primary receiver (set-top box) that is the recording one and two secondary receivers on my other TVs.  One of my secondary boxes has been freezing during playback of recorded programs.  It only happens on that one box.  I have