Sorry, I had to dig through my emails to find the solution that worked.
From Roku, Dec. 2021:
We suggest you follow the steps below:
Connect the Roku to a different HDMI port
Disable the screensaver (Press the home button >> Settings >> Themes >> Screensaver >> Change wait time >> Disable screensaver.
Set the display type as auto-detect (Press the home button on the Roku remote >> Settings >> Display type >> Auto-detect >> Ok go to automatic >> Select yes the screen looks good before the timer ends)
Press the home button >> Settings >> System >> Power >> Auto power savings >> Uncheck Reduce power after 20 mins)