[12.0] Random shows locked on "watched" status

Description of the bug

After the upgrade to 12.0, half or more of my unwatched tv shows are marked as watched. The choice appears to be random. This cannot be undone. They can't be changed back to unwatched.

Reproduction steps

I open Jellfin and find a show that I haven't watched that has a black checkmark in the upper right of the poster. I try clicking the red checkmark in the various places it appears (when hovering over the poster, or at the top of the show's page). It turns white. If I refresh the page or go into the show or season, it's red again. Such a show, its seasons and episodes, and even any collection containing it, cannot be changed to unwatched status.

What is the current bug behavior?

The show, etc. remains in "watched" status.

What is the expected correct behavior?

1. That shows that were unwatched before the upgrade should remain unwatched.
2. That, after manually setting them to "unwatched" they should stay that way until they are actually watched.

Jellyfin Server version

12.0

Specify commit id

No response

Specify unstable release number

No response

Specify version number

12.0

Specify the build version

12.0

Environment

- OS: Linux
- Linux Kernel:Mint
- Virtualization:Docer (portainer)
- Clients:Web
- Browser:Firefox
- FFmpeg Version:? stock?
- Playback Method: N/A
- Hardware Acceleration: N/A
- CPU Model: Synology?
- GPU Model:
- Plugins: Artwork, AudioDb, Fanart, IMVDb, ListenBrains, Merge Versions, Musicbrainz, OMDb, Open subtitles, Playback reporting, Studio Images, Theme Songs, TMDb, TMDb boxed sets, TVmaze
- Reverse Proxy:
- Base URL:
- Networking:
- Jellyfin Data Storage & Filesystem:  Synology (SSD)
- Media Storage & Filesystem: Synology (HDD)
- External Integrations:

Jellyfin logs

I'm not sure if this is the error:

[2026-09-08 00:00:00.006 -04:00] [INF] [54] Jellyfin.Plugin.PlaybackReporting.TaskCleanDb: Playback Reporting Data Trim
[2026-09-08 00:00:00.025 -04:00] [INF] [54] Jellyfin.Plugin.PlaybackReporting.TaskCleanDb: MaxDataAge : 12
[2026-09-08 00:00:00.029 -04:00] [INF] [54] Jellyfin.Plugin.PlaybackReporting.Data.ActivityRepository: DeleteOldData : "delete from PlaybackActivity where DateCreated < '2025-09-08 00:00:00.0252115'"
[2026-09-08 00:00:00.030 -04:00] [INF] [54] Jellyfin.Plugin.PlaybackReporting.Data.ActivityRepository: Default journal_mode for "/config/data/playback_reporting.db" is "delete"
[2026-09-08 00:00:00.042 -04:00] [INF] [54] Emby.Server.Implementations.ScheduledTasks.TaskManager: "Playback Reporting Trim Db" Completed after 0 minute(s) and 0 seconds
[2026-09-08 00:00:01.001 -04:00] [INF] [54] Emby.Server.Implementations.ScheduledTasks.TaskManager: Daily trigger for "Playback Reporting Trim Db" set to fire at 2026-09-09 00:00:00.000 -04:00, which is 23:59:58.9989650 from now.

FFmpeg logs

Client / Browser logs

No response

Relevant screenshots or videos

No response

Additional information

No response