Plex Movie Metadata Agent has the wrong year for Unthinkable

Plex should default to the first “theatrical” release date. Film festivals usually don’t count.

Did you tell Plex to “prefer embedded meta tags”? The wrong date could be stored inside a mp4/m4v file.

Only if you still use the old deprecated agents (i.e. NOT “Plex Movie”):
Perform only the first 3 steps from this guide: [HowTo] Reset metadata agent preferences to defaults and whack caches

There were a few date-related bugs in PMS 1.26.0 which have been fixed in PMS 1.26.1 Please update to this beta version and re-evaluate.