I updated the firmware on the AVR, and checked settings. HDMI inputs are mapped correctly. It's set up the same way it has been for over a year. Still no picture or sound, with the same error message on the TV “No signal.” Testing finds the Roku delivers signal to the TV and works fine when directly connected to the TV by hdmi, bypassing the AVR. The Roku works. it just won’t pass through the AVR anymore.
It’s a mystery.
Since the Roku shows up when routed directly to the TV but not when routed through the AVR, logic says there's something going on with the AVR In the thread I posted about upgrading to the Ultra most seem to plug it into their TV rather than an AVR and run ARC from the TV to the receiver for audio. Have you tried that mapping?