The way MCEBuddy is designed, metadata is taken the following order:
- Parse Filename for metadata
- Overwritten by embedded metadata
- Overwritten by NFO metadata
- Supplemented by Internet downloads (or replace if option is selected in the Metadata Corrections page)
You can’t disable metadata extraction but if you have your own NFO file it will overwrite any extracted metadata (consider it a manual override option).
There is also a metadata correction page, have you tried using that?