I have the same issue on the Trakt website. Trying to mark an episode as watched brings me to my dashboard while at the same time adding a message in red at the top of the website saying: “You’re already signed in.”
The strange thing is tv episodes and movies I’ve already watched and have added to my watch history on the Android app, also appear as unwatched on the website. They do appear in the recently watched section but the purple checkmark is missing and there’s no watch history to be shown.
I’ve already deleted my browsers data, this doesn’t have any effect.
Thanks! I removed that extension and disabled EasyList Cookie in Brave. When I opened the Trakt website, it asked me to accept cookies, and now everything works.