I have a number of Shows/Episodes that have suddenly appeared back on my Continue Watching.
All of them are old shows.
I have cleared a few by adding Unknown Date as the watched date but some, as in the pics, have the tick to mark as watched greyed out.
2 Questions:
In this show the ones unable to mark watched are S4 E14 and S5 E5 to 12.
Happens often to me too. Used to happen also in V2.
My guess is that smthg changes on this shows like on TMDB or wherever they take the data from and during sync that markes them as unwatched.
I get this occasionally, mostly with special episodes when someone changes things on tmdb
The reason for the watched box is greyed out (S12 E5), is because it doesn’t air for another 8 thousand years, air date of Dec 31st, 9999, not sure when it airs/aired, but if that date is corrected on tmdb then it should allow to mark as watched
“The reason for the watched box is greyed out (S12 E5), is because it doesn’t air for another 8 thousand years, air date of Dec 31st, 9999”
I never noticed that, thank you. I’m an old git so doubt I’ll be around then 
Looks like it has been modified to how the episodes aired in another country, quite a common occurrence for UK shows
Some international streaming platforms, digital storefronts, or region-locked listings (like JustWatch or Prime Video variants) occasionally split or re-label late UK episodes, specials, or the 11th series roadshows as a 12th season.
It is beyond my pay grade to know how to fix this, looks like one for trakt support
