I enabled the option to check for AV receivers in the model search via the hidden menu, and still, with my Roku Ultra LT, I am not able to find any AV receiver brands.
I've done a complete cable removal and power cycle, it's not a handshaking issue.
HDMI CEC is enabled on my receiver.
I know there's a disclaimer on the Roku screen when you attempt to set up volume control that it doesn't work with receivers/soundbars, but, I've read here that others have it working and, well, that's just a stupid restriction that should not be present. What difference does it make if the IR receiver is a TV or AV receiver??
The appleTv 4k remote works and controls the volume of my receiver without issue. Not sure why it's so hard with a Roku.