I would suggest remove current AMD drivers and installing 12.6 Beta drivers.
Prior to these HDMI had problems much as you describe.
There are now 3 flavors of 12.6 beta, I have used the first or oldest but have heard the second worked as well. The third I have no info on.
Vizio P75-C1 | OPPO UDP-203 | Samsung UBD-K8500
Denon AVR-X4300H00 | Nvidia Shield Android TV | C =Axiom VP150 |FL/FR =Axiom M60 |SL/SR =Axiom QS4 |TFL/TFR =Bose 161 | TRL/TRR =Bose 161 |Sub =Reaction Audio S-15 500W SEALED SUBWOOFER