Older episodes are not showing up and not playable on Seasons menu.

May 22, 2021

Symptoms
- Older episodes are not showing up on Seasons menu.
- Older episodes are not showing up on Metadata Manager menu.
- Older episodes are not playable when I click the play the season button.
- However, those missing episodes are not only still searchable, but also playable via search.
- I'm not sure when this problem began. I upgraded to 4.6.0.50 a few days ago, and found these symptoms today. However, I think it could date back to February 2020, because among the episodes I've checked randomly so far, everything I got before February 2020 exhibits the same symptoms, while everything I got after March 2020 does not exhibit any of these symptoms. I couldn't manually checked them all, since I got tens of thousands episodes.
- The following is an example of the partially broken season (/TV Shows/Young Sheldon/Season 3/).
- EDIT: This happens only on TV Shows library. No problem on Movies library (at least I've found none so far).
Things I've tried and failed to resolve the issue
- Show > More > Scan Library Files
- Show > More > Refresh Metadata
- Show > Season > More > Scan Library Files
- Show > Season > More > Scan Library Files
- Manage Emby Server > Library > Scan Library Files
- Manage Emby Server > Library > TV Show > Scan Library Files
- Manage Emby Server > Library > TV Show > Refresh Metadata
- Manage Emby Server > Scheduled Tasks > Scan Metadata folder
- Manage Emby Server > Scheduled Tasks > Scan media library
- Manage Emby Server > Scheduled Tasks > Trim Db
I want to resolve this issue;
- without a complete reinstall, or any method that could trigger the reset of the existing metadata, because a) I've manually changed a few dozens of incorrectly identified metadata and I couldn't recall which one, b) I don't want to reset playback history.
EDIT - Possibly it's fixed after I shutdown Emby on web interface and relaunch the emby service. Verbose explanation follows;

I found one weird thing going on. Long time ago, Emby dropped the install as a service, so I started to use NSSM to launch it as a service (which is the one showed up as Emby Sever 3.4.1.0 on the screenshot below). Up until very recently, I remember it works just like a service. When it's running, services.msc says it's running (like DNS Client or DTSAudioSvc below). When it's not running, it's empty. However, everytime I update the Emby server, the installer shutdown the service and launch itself as executable; resulting in emby tray icons and non-active service. So I had to shutdown the Emby via tray icon or web interface, and relaunch the service.

However, after this update (which was initiated automatically via my script), there was no emby tray icon for some reason. Also, right after I tried to launch the service on services.msc, it said Running, so I haven't doubt that it's running as a service. However, when I right-clicked the service, it only gave me 'start' option, which isn't right for the running service (it should give me 'stop' and 'restart') and correct for non-active service. So I shutdown the Emby via web, and launch it as a service.

After the relaunch, I initiated another library rescan, and it seems early episodes are started to pop up again. TV Shows that starts with 0-9 and a-c came back already.