Server Version#: Docker on UnRaid
Player Version#: 4.136.1
<If providing server logs please do NOT turn on verbose logging, only debug logging should be enabled>
Using “Plex Movie” as the metadata lookup
There seems to be no movie by that title released in 1984.
look carefully at the 1980’s hair styles 
That movie was released in 1998.
It might be set during the 1980’s, but that doesn’t make it released in 1984.
The number 1984 also doesn’t appear to be part of its title anywhere in the world. The Wedding Singer (1998) - Release info - IMDb
So it is no wonder that Plex is not able to find a match, if you explicitly tell it to find a movie released in 1984.
