I am having the same issue as this: ATV4K Video Rotated - Channels Apple TV - Channels Community from 2023. Does not look like it was ever answered. Is there a fix that does not require converting the files?
on apple tv a video shot in portrait is rotated and displayed in landscape... same video on the webapp looks fine.
Legacy mode driver fixes it, but as I understand it loses functionality elsewhere.
Is there a fix for this???