I’ve noticed that after the last update (to version 55) episodes that i marked as watch on Trakt do not become watched in an app, like it used to be. Usually when I tapped on a show that I marked as watched on Trakt, it synced immediately and marked certain episodes as watched. But now even deleting a show from Series Guide and then adding it again does nothing. I tried “Sync and Update”, tried deleting cache – nothing helps. Now the only way for me to mark an episode as watched is from Series Guide, otherwise it is shown as watched on Trakt and unwatched in Series Guide.
I can concur that this started for me with the update. I can rate and check into an episode and it shows up on trakt but if I mark it as watched it will not show up. It also has not synced any episodes on SG since the update. I can check into the episodes and they show up on trakt as watched but never show as being watched on SG.
Edit 7/21/20: As of today, the issue seems to have resolved itself for me. Will update if the problem occurs again.