I have a home theater PC that I recently installed a Vega 64 into. I have a Denon x1500H AVR which was previously connected to a GTX 960 and another way older Nvidia card with no issues. It seems that my PC is not even booting when connected to the AVR (no drive activity light). The only way I can get video at all when connected directly to the AVR is to unplug the HDMI cable, boot the PC, and then reconnect the cable once Windows is loaded. This sort of works, but is not able to do HDR, etc.
Is there anything I could possibly try? I've tried different inputs on the AVR, different cables, updated everything, and tried a couple different displayport->hdmi adapters (works reasonably well, but still has issues with HDR). I'm going to see about contacting Denon support as well.
After looking around on here, it sounds like AMD cards unfortunately have a lot of problems with AVRs and HDMI sound, so I'm assuming I'm probably out of luck until I can get my hands on a different one. Luckily I can use ARC in the meantime through my TV, but I'd really like to be directly connected to my AVR.