I just bought an LG C2 and was using an Onn Android TV stick to watch Plex. No issues for a week then out of the blue it stopped playing Dolby Vision. I get Audio (with the Dolby Atmos badge) but no video. I swapped out for a Google Chromecast 4K and it works fine.
I also tried the Onn on another Dolby Vision capable TV and had the same issues. That TV plays DV fine as well using the Chromecast and its own built in Google TV system.
The Plex settings are the same on all setups, there is no transcoding going on.
This leads me to believe it's something with the Onn Android TV stick.
Any guidance would be helpful.
As far as I know the Onn does not support Dolby Vision. The video should fall back to HDR10.