Write down what you finished
Open the series page and find Seasons & your checkpoint. Choose the season and the last episode you completed, then save. A reminder saying “last completed” is less confusing than a bare episode number that could mean either watched or next. The reminder does not advance when you click a poster.
Coming back after a lost history
Start with the strongest clue: the show, the season, or the last event you remember. Check episode information in the viewing edition before reading a full recap. If the recap covers material you have not seen, it can reveal more than you intended. Rebuild only the part of your history you can identify confidently.
Keep related shows separate
The Boys and Gen V have distinct entries and reminders. A checkpoint for one should not become your place in the other. The same principle applies to a prequel, a remake or a show with editions from different countries. Confirm the production before deciding that its season numbers match the ones you remember.
After moving to a different device, use the list backup when you want to bring the reminder with you. Merging keeps a checkpoint already present in the receiving browser. It does not import an old account from another Flixtorz-named site.