Those years in parentheses are probably included in the embedded ‘Title’ tag in your mp4 files.
Go to Settings - Server - Agents - Movies - Plex Movie
In there, grab the line ‘Local Media Assets’ with your mouse and drag it downwards, so it ends up being at the bottom of the stack of active agents.
Do the same under
Settings - Server - Agents - Movies - TheMoviedatabase
and
Settings - Server - Agents - Shows - TheTVDB
and
Settings - Server - Agents - Shows - TheMoviedatabase
Afterwards Refresh the affected movies.
