I know what the manual says, and I’ve been deciphering many different manufacturers’ manuals for many years. Unfortunately, I don’t have this unit to confirm, so you’ll have to try this on your own, and not take my word as gospel. The manual, as many are, is a bit confusing about it, but it doesn’t seem that you can have HDMI Control
AND Standby Through – “On” simultaneously. Try turning HDMI Control “Off”.
I’m not sure if other Yamahas work this way, but it seems contrary to the way other brands work: HDMI Control needs to be “On” for the Standby Pass Through to work.
Actually, rereading the note, the Standby Through should not be available for setting if HDMI Control is “On”.
This parameter is not available when ‘HDMI Control’ is set to ‘On’