Problem connecting AppleTV to Yamaha Aventage receiver via Airplay

So, i have a projector setup far away from my Yamaha RX-A2070 whole-home receiver and want to connect the AppleTV (4k version, purchased new 8.2022) to the Yamaha via Airplay to put sound from projector through our home stereo speakers. If I Airplay from my phone when streaming TV, it works fine. But when i try to connect our AppleTV via Airplay, it connects for ~0.5 second with clear audio then stops working. I've tried adjusting every setting i can find in the Yamaha receiver without success along with changing settings on the AppleTV as well. The frustrating things are that 1) my phone and iPad can Airplay just fine and the AppleTVs (have tried two now!) cannot; 2) it connects briefly so i know it can connect; 3) i purchased this new AppleTV recently because i thought it was a problem with our older AppleTV but that didn't fix it. Any help is much appreciated!!