Have you tried firing it with the new recoil spring installed ?
I bought a P13 lightweight in 94' and had the same exact issue with it out of the box.
Tuned the extractor, no change. Replaced the ejector and extractor, no real change.
What solved it on my gun was a stronger recoil spring.
Haven't had an issue with the gun since, although within a year just about everything but the frame, slide and grips were upgraded to Ed Brown and Wilson parts.
Also be sure to replace the magazine springs from time to time, especially if it develops feeding issues.