As most everyone has figured out, the problem is the screensaver. If you like the City Stroll screensaver, I discovered a workaround other than changing screensavers: resume playing the paused show by pressing the LEFT direction arrow instead of pressing OK or PLAY. This solved the problem for me!
Thanks for letting us know about the issue you're experiencing.
The resolution provided by @StreamerUser might help. Try giving it a shot! If still no luck, we suggest reaching out to YouTube TV support directly to report the issue and for further help. Channels on Roku are maintained by the developer themselves. In this case, there's likely an issue within that specific channel that needs to be addressed with an update from them.
You can contact them here: https://support.google.com/youtubetv/gethelp
I found the same thing using the back button. Odd that doing what you think should take you back actually moves you forward and I changed my screen saver...there are hundreds out there I choose some winter scape and it wasn't on the do or don't list but it didn't work. I haven't tried the exciting digital clock.
So after having tried the digital clock screensaver the problem still occurs. My sense is that the digital clock screensaver in comparison to animated full screen saver doesn't use as much memory and lasts a little longer.
I don't know where the "paused tv buffer" is saved but assuming it's on the Roku it could only hold so much and eventually craps out. if you've saved what you are watching it shouldn't be an issue because that would be done by the app provider ie Youtube and it should beable to restart where you paused because the entire show is saved.
I've not verified the saved show theory to see if it works but if it does the work around is to save the show you're watching.
Read back through the posts. When you pause YoutubeTV or Youtube the screensaver comes on. When you attempt to restart your show, depending on the length of the pause, if long enough it will fail to restart your show at the paused location. You are returned to the Main Roku Menu, not even still in Youtube, at which time Roku starts to load a random channel
There seems to be an odd work-around of using the "return to prior screen" instead of the pause button to restart which seems to start your program at the paused location. It will play for a few seconds and stop at which time you have to press play button to keep it going. This may only work for a certain time once the pause is pushed. It's hard to know.
There's also been a suggestion of changing your screen saver to certain screensavers solving the problem but I think these lighter weight memory using screensavers are just extending the amount of available memory.