I had only 2 FTF but over 20 FTE. Can a mag interfere with ejection? I did have trouble loading 10 rds. into the Wilson mags.
If you do not have trouble with 9 rounds in the mag but you do with 10, I will suggest you try a mag with the flat spring follower. I would think that a bad extractor would fail to eject whether there's 8-9 or 10 rounds loaded. However, I am not an expert.
Best regards.