Collections are not using Thumbnail images properly

[impactvolly]

I'm running Jellyfin version 10.10.7 and have run into an issue with collections and how images are being handled.
When a collection has a Primary Image, a Backdrop, and a Thumbnail, Jellyfin seems to ignore the Thumbnail. It picks the Primary Image first, then the Backdrop. It only uses the Thumbnail if it is the only image available.

I have made sure the collection metadata is unlocked. I have also uninstalled and reinstalled the TMDb Box Sets plugin. Neither of these changed the behavior.
I don't want to manually set the Primary Image because I still want the Primary, Backdrop, and Thumbnail to serve their normal roles. I just want the collection to correctly use the Thumbnail for its preview instead of defaulting to the Primary Image.

Deleting the Primary and Backdrop forces Jellyfin to use the Thumbnail, but as soon as I re-add them, Jellyfin switches back to using the Primary or Backdrop.
The collections exist on TMDb, and I have tested with several. The problem is consistent.

Is there any known way to change the image priority for collections, or force Jellyfin to use the Thumbnail as the main preview image?
Any help would be appreciated.
Thanks.