Me too! I posted on another Cox page a month ago about how it was not working on my host box in the living room but worked on my client box in my bedroom and nothing from COX! Then a few days ago the app wasn't working at all and I kept getting something like WE are having trouble with this app right now try back later. Then it when it loaded up the back wouldn't work on my bedroom box anymore. After multiple app resets and system restart and finally system reset I got the bedroom app working with the back button again. I looked at the youtube APP version (at bottom of settings page) and it had reverted back to version web_20200708_00_RC00. I actually got my big box in living room to do the same. Back to that same web version. Thought I was finally all set and it's fixed. Yay. Then the next day it updated and to web_20200722_00_RC00 on both boxes and no more back button on youtube on either of the boxes no matter what I do. Sorry for the long post but maybe someone might know something. And I don't mean Cox, because apparently they don't give a **!
The EXACT same scenario happened to me! I'm glad you've taken the time to detail it. I really don't think they are working on a solution at all. It's a horrible user experience, either way.
