This is going to sound weird, but you might try fully removing the stick from your TV for a while (to make sure it isn't getting any residual power from the HDMI connection).
I finally gave up on trying to debug the stick that was giving me this problem. I ended up using the streaming apps on one of my smart TVs so that I could rotate my other roku devices around a bit and take the problem stick out of service. The odd thing was that I re-attached the problem stick a day or so later to do some more experimenting, and have been unable to replicate the problem since. The only thing I can think of is that the HDMI connection was keeping the stick partially alive when the USB power was removed.
I found that Anynet on my Samsung TV is turning the ROKU steaming stick off after ten minutes. However when I turn of Anynet, my sound system receiver won't work but the turn off problem disappears. When I use my Samsung blue ray player to stream everything works. The problem is the Samsung blue ray player is very limited and won't steam popular sites like HULU. My equipment is obsolete!
Sadly, I started to get this problem with an older Roku. So I spent what little money I had left on a streaming stick+. But I'm still having the issue. Whenever I pause long enough for the screensaver to pop up, I returned to watch by pushing play and it had already disconnected me. We're talking less than 10 minutes. And it happens every single time.
I've tried disconnecting it. I've tried restarting it. Nothing changes.
I wish I hadn't spent the money on an "upgrade." At the time I didn't realized that there was a version with a headphone jack and one without. So now I'm stuck without a headphone jack, and the problem isn't fixed. 😕
I've noticed that lately pressing play to exit the screensaver launches the Roku Player App due to embedded ads on the billboards, which is infuriating. Will have to hunt for a setting to disable the screensaver now (which is a shame as I don't actually mind it as a function, and I actually kind of like the design of it).
As for the topic's issue, I've just noticed it happening to me today at the 30 minute mark (I was watching Netflix last night and it's debatable whether it happens on there). So far effecting (affecting?) Plex and YouTube. Just tried the system restart and that seems to have done the trick, as I've just managed to get through a 39 minute video on YouTube without any issues.
Yea saw this advice and now my tvs complete garbage, it uninstalled everything (I was thinking restart the TV not reset or erase everything you have) have to log in manually to every channel now after trying to add it, lost all my random channels, forgot half of the logins for the apps I had, and now with only like 4 apps it's saying I can't add YouTube because there's not enough space, I had like 30 apps before I "restarted" the TV. Everything loads slower now too and prime always says I have to redownload it. I would have rather dealt with the going back to home screen randomly while watching something sometimes vs lose pretty much everything/have everything go to shi* , great advice man appreciated it smh