That’s the expected behavior, and the expected improvement in MKV playback behavior on a DV-capable system with app version 8.6. (With some questions about why Plex activates HDR10 output mode instead of DV mode.)
Plex itself isn’t tone-mapping DV. When connected to a non-DV TV, the Apple TV doesn’t announce that DV is available.
It’s very interesting that the Apple TV 4K is capable of tone-mapping DV to either HDR10 or SDR when set to those modes, but only when the Apple TV 4K detects a DV-capable TV. I wonder if it’s a naive capability check, or if it’s a licensing entitlement check.
But if it’s a non-DV capable TV, the Apple TV won’t decode DV itself. So in that environment Plex isn’t expected to play DV P5.
Infuse is doing something different, and appears to perform tone-mapping in the app itself.
