Plex Server does not mark played videos as watched and does not synchronize status

Plex Media Server
,
1

Windows Server Version#: 1.32.6.7557
Synology Server Version#: 1.32.6.7557
Player Version#: Web interface (Firefox) + Android 10.0.0.4149 (c2617d8)
<If providing server logs please do NOT turn on verbose logging, only debug logging should be enabled>

Hello

I could not find a related question, so please excuse me if this is a duplicate topic.
I am a lifetime subscriber and I’ve been happily using Plex since many years.

Issue 1
I recently setup Plex on my Synology in order to backup my Windows 11 server.
After a few days, the 2 servers stopped to synchronize watch status and rating, although the feature is set in the preferences.

Issue 2
Also, since some days, when I watch a personal video in a huge library the video is not marked as watched (and of course it is not updated in the other server.

The 2 issues happen regardless of the client used.
I tried to restart the server(s) and restart the computer/nas, but nothing changes.

Any suggestions would be appreciated.
Thank you
Stefano

2

Adding logs…
Synology Plex Media Server Logs_2023-10-02_11-53-59.zip (3.8 MB)
Windows Plex Media Server Logs_2023-10-02_11-53-41.zip (3.5 MB)

3

Further info: it seems like this happens only in one library, while the others do not have this error.