HELLO:
I must be dumb because I could not post this on the pages for Zoomed In Screen that 12 other folks did. But....same issue. All cables are secure, correct and are high quality for my Roku Ultra. It happens across various channels. I also noticed that the device turns off after a few minutes in screen saving mode which it never did before. All connections are correct, wifi has been reset (repeatedly), software updates installed. This issues started a few weeks ago. I shouldn't have to unplug every week. Please send answers/remedies to lrsscott@yahoo.com
Thank you.
Re idle turn off issue:
My guess is your problem is caused by a change introduced by Roku operating system version 10.5. It added added a new "Power" item in the "Settings > System" menu for some of the latest Roku models.
If you have a "Settings > System > Power" menu item, under "Auto power savings" see if deactivating any power saving options you find there keeps the Roku from shutting down.