If it's pulling the case out of the chamber but not throwing the case out of the rifle then the extractor spring should still be present and sounds like extractor is behaving normally. To me it sounds like a failure to EJECT rather than extract.
Which would point to ejector in my mind or apparently a short stroke but I'm not so sure on the latter.
Seems like a pretty rare problem.
Whats the rim of the casings look like after fired?
FtEj is often a sign of a short stroke; check that the ejector fully telescopes under the bolt face. The ejector spring should be VERY stiff. The ejector spring is, should be, the same spring as the one used under the selector detent, consider it a spare.