In the settings, there is an option to change the nightly reboot time. Try to pick a time that you are unlikely to need the TV.
Settings/Preferences/General/Daily Update Time.
Yes I know and that update is usually set to a time at night when I am asleep but this is not the same interruption. The nightly reboot used to go off for a few minutes and then welcome to xfinity we're restarting your services or something to that effect with black screen but this is a New problem with the message in the above title and blue screen and it affects the internet as well going on and off several times during the night vs the one time per night reboot of the cable boxes. I tried rebooting the modem via the xfi app but that didnt work; I had the automated phone system do the same but didn't work so I called back and then the automated said something to the effect of finding errors in my system and a reboot should fix them. So far it has.
We did just get a newer modem and I suspect that might be part of the problem and that cable box is a newer one too. But again so far the automated phone systems reboot AFTER they found errors in my system seems to have fixed it. Probably one of their updates caused it in the first place but it is not unusual to receive defective replacement equipment and have to call for replacements of the replacements.
I'm just tired of covid being the excuse that no one can answer the phones anymore. The local store closed because of covid so we would have to travel an Hour one way to get to a physical store. Other companies have agents working from home answering the phones and their stores are still open for business, so the giant XFINITY COMCAST should be able to do the same operators at home and store open but they aren't.