TV Show not being marked as watched after watching



In fact, the episode rewinds about 4 minutes and remains showing unwatched.
If you try to manually mark the item as watched, it doesn't work. (typically doing this on Plex on Apple TV)
It also doesn't work trying to mark a watched item as unwatched

If I do it using Plex media Player ( Mac OS X) the I get the error
"There was an unexpected error marking an item as watched"

I've tried doing it form every angle (whole season, on the server, on Apple TV, on iOS etc, same result)

This is getting really annoying- being unable to easily determine which shows are watched or not

any ideas/solutions?

Mac OS X 10.13.4


FYI The issue ended up being a damaged library file (Library/Application Support/Plex Media Server/Plug-in Support/Databases/com.plexapp.plugins.library.db)
Actually the library file was on a damaged sector on my hard drive, after deleting the file and rebuilding all the libraries, everything is working fine .
( I actually cloned my whole drive to a new one then rebuilt the library’s