Update: Seems like update 1.25.6.5545 solved the problem.
Server Version#:1.25.5.5492-12f6b8c83
So plex is not updating series anymore. I have to manually go to the series folder in the library en press refresh metadata. Few versions ago it updated automaticly if i copied a new episode a folder. Now it is just continuously, all day, scanning all libraries, and not updating new shows.
I did update the movie database, just not the series database. After update of movie database all my costum cover art and info was gone, so im a little hesitant to update the series database.
Did fresh update of ples server and restarted my nas couple of times (usually helps). Also turned off local media assets (TV) someone gave that tip. didnt help.
Any tips?
There have been a few threads opened for this in the past couple weeks. Issue appears to be that the scanner is hanging. Downgrade your Plex server to version 5409 and it should fix the problem until Plex can issue an update.
Adding in that this is happening for me, as well. Rolling back to .5409 stopped it.
Make backups, but rolling back is easy. Just stop the PMS package on Synology, uninstall, then reinstall the older Plex version. It takes maybe 2 minutes altogether to get back up and running.
On Synology, the application (package) is stored separately from the server data.
This is what allows easy change: Uninstall with keep option then reinstall new version.