Extractor Adjustment?

[ee2]

I replaced a broken extractor on my Star Model B 9 mm with a replacement part from Numrich. It needed some polishing to fit (a little too thick to fit the slot and too coarse on the rounded bump to fit flush). With a little smoothing it fit well and functioned OK when cycled by hand with either dummy rounds or live FMJ ammo. Feeding from the magazine was smooth and extraction and ejection worked when I cycled the slide by hand. Live fire was a different story. Every shot left a shell in the chamber even though the action cycled. If I loaded a single round from the magazine and fired, the action cycled cocking the hammer but leaving the shell in the chamber. When I pulled the slide back by hand, the empty shell ejected neatly. Any advice on what's wrong and how to fix it? Thanks for any and all help.