Between 2 homes, we collectively have 5 Roku 4s, 4 Roku 3s and a Roku TV…
EVERY ONE of them with the Roku 7.1 software does randomly get kicked back to the menu.
It also happens on many other Roku Apps I use, from Syfy to PBS & the Disney Channel. I found a few mentions of it on the Roku forums as well as others here.
Here are a few though I know i read others, just don’t have time to find them right now.
https://community.tablotv.com/t/tablo-exits-out-randomly-watching-recorded-show-roku
Good news is that the two units that have updated to 7.2 have not had this issue but its still early…