SOLVED: Jellyfin and Kodi not syncing

[Mookmeister]

After some issues with MySQL and Kodi, I decided to move over to Jellyfin and continue using Kodi as the front end. After installing Jellyfin on my Synology NAS, I added the Kodi Sync Queue plugin (also the Trakt plugin, but more on that later). I installed the Jellyfin for Kodi addon in Kodi and loaded the libraries from Jellyfin; I assume this was successful as I can play movies and shows on Kodi. The watched status of movies and shows on Kodi and Jellyfin aren't syncing, however, so the watched status is correct on Kodi but not on Jellyfin. Also, new movies/shows added to the Jellyfin library aren't syncing to Kodi.

As mentioned, I also have the Trakt plugin for Jellyfin. It appears that the Trakt plugin has synced the watched status on Jellyfin to Trakt, so that my watched history on Trakt is gone. It still exists on Kodi, so I'm hoping that I can get the Kodi-Jellyfin sync working and transfer over the watched status from Kodi to Jellyfin initially, and then Jellyfin to Trakt. More generally, I'd like to get the sync to work properly so that Jellyfin library updates are reflected on Kodi and watched status is pushed from Kodi to Jellyfin after watching.

Any help would be appreciated.

[mcarlton00]

This sounds like you might have a broken websocket connection between your Kodi and your server. Websockets are used for real time reporting of watched status. If you're using a reverse proxy it could be misconfigured, or you could have had some network stability issues that caused the connection to drop.

The other alternative is that you had existing items in your Kodi database before syncing Jellyfin metadata and it's possible those are being used for playback, going directly to the files instead of using the Jellyfin server.

[Mookmeister]

This sounds like you might have a broken websocket connection between your Kodi and your server.  Websockets are used for real time reporting of watched status.  If you're using a reverse proxy it could be misconfigured, or you could have had some network stability issues that caused the connection to drop.

The other alternative is that you had existing items in your Kodi database before syncing Jellyfin metadata and it's possible those are being used for playback, going directly to the files instead of using the Jellyfin server.

Your second point prompted me to look at the advancedsettings.xml file for Kodi and sure enough it still had the reference to MySQL. I removed that and also deleted the source.xml file, which contained the SMB share path. I then uninstalled and reinstalled the Jellyfin for Kodi addon (probably wasn't necessary) and confirmed that the movies/shows are now pointing to Jellyfin. To test, I marked a show as watched on Kodi and that was reflected in Jellyfin and Trakt. So, all is good now.

My watched history on Kodi was wiped so there's no way to automatically update Jellyfin (or Trakt). I did at least have the forethought to take a series of screenshots of Kodi so that I have a record of what I've watched and can update when I have time.