Server Version#: 1.21.1.3876
I got a bilingual library. Meaning the main language is english with about 95% of movies in that language. The rest are German movies. For those movies I corrected the match with changing the agents language for that entry.
Now I transition from TMDb Agent to Plex Movie Agent and I perform a metadata update for all entries. All movies which I corrected the match for are beeing updated with english metadata again, ignoring my manual match.