I have gen 2.5 26 with cast extractor and non-lci edp and a gen 3 17 with non-dip LCI extractor. I field stripped both guns and placed a 9mm case under the extractor to test how the case was held to the breechface. Both extractors held the case tight with little to no movement. I tried the cast extractor, non-dip lci, dip lci, and apex extractor in my problematic gen 3 19. All extractors failed to hold the case firmly to the breechface. I am convinced this is the reason for my erratic ejection.
Someone postulated that the cutout for the extractor in the slide was machined wrong and causing erratic ejection. I'm starting to think that is what is wrong with my gun.