Unsupported File Format

Trying to use the DS Video app on the Apple TV 4K and one particular series of videos won't play. I get an error "The format of this video is not supported". It's an MP4 HEVC AAC_lc codec. Which plays just fine on my Android Tv using its DS Video app. (All other videos on the DS are mp4, avi and mkv files and they play fine). I noted that the android tv will ask you if you want to install a third party player each time you open some of the videos but you don't have to it will play with either native or third party. There is also an app settings option to "always use third party" or not (I believe it's MXPlayer) but Apple TV has no such in-app setting which leads me to believe I can't install a third party player. Vlc and plex are on it but they don't lend a hand here. (On the Android tv often in the past when playing certain videos through the DSVideo app; Vlc has opened it automatically instead of the native player).