KenMasters
Super Moderator
How was the PS5 connected to the amp if it wasn't eARC before?
Everything connects directly to the Denon, then the Denon to the TV. No need for eARC (normally).
The C9 was the first TV with HDMI 2.1, I can't remember the exact details, but they beat everyone else out by a year by grafting a 2.1 chipset onto their existing HDMI 2.0 board - I'm thinking maybe this is the problem. I'm still waiting on delivery of my G3, we'll see if that resolves the issue.