Atmos/4k Streaming Issues

I'm having some bizarre issues getting my Shield to work smoothly and am at my wits end.

Here is my system: 2019 Shield Denon 3800h Receiver running my 5.1.4 system newly built. Epson LS12000 4K projector.

Running direct streams through Plex, I can stream full 4k Atmos content without any issue, sounds incredible with no transcoding.

Any non 4k or non Atmos (not fully sure which) content on the Disney or netflix apps work perfectly.

Anytime I try to play a 4k or Atmos stream on the built in apps it gives me an error from the Disney or netflix app and will not play. Sometimes it seems to try for a second and then fail.

Things I've tried: ensuring the Denon is set to Dolby Surround/Atmos mode (not DTS), changing shield between pass through or Dolby audio processing, ive also tried playing with nearly every audio or video setting I could find on the Shield but nothing seems to be work.

Every now and then between changing settings and resetting the shield it will play, but then if shield sleeps and I come back to resume the movie it will stop working again.

Could this just be a defective Shield?

Grateful for any troubleshooting tips you guys can provide!