Hover text in ‘Continue Watching’ indicates it will remove watch history
Detailed description with additional context about the workflow
On the home screen, in the ‘Continue Watching’ section, when hovering over the check box to mark an episode watched, it shows text for “remove from watch history” if you are doing a re-watch.
For episodes that have no watch history, it shows the correct “mark as watched”.
Clicking appears to do the correct thing of adding a new watch history.