Infuse 6.1.1 on tvOS 12.3.
Relevant Infuse settings:
Watched Indicators: On
Each movie collection poster has the unwatched symbol in its upper right corner (the orange triangle containing a dotted circle). Yet none of the movies in those collections have the unwatched symbol on their posters. I have tried the following as a workaround but ultimately it doesn't work:
1) Long press on the collection poster, and choose Mark as Unwatched (after which all the movies in the collection have the unwatched symbol).
2) Long press on the collection poster, and choose Mark as Watched.
3) Observe that the collection poster doesn't have the unwatched symbol anymore.
4) Launch the tvOS Application Switcher and swipe up on Infuse to force quit it.
5) Launch Infuse again, navigate to Movies, and observe that the collection has the unwatched symbol again (and the movies in the collection remain watched).