[DonVoigt]

Aftermarket ejectors are often tough, and require judicious filing of the round locating/securing projection to lock in.
Sometimes/frequently they are too long and rub at the front, the ejector must move freely through the slot and enter its cut out fully to function correctly.

Occasionally they just won't fit and you will need another; originals are best, but sometimes they just won't fit either.

Of course you need the later "new model" ejector, the ejector for the "old model" ejector looks the same but the projections are in different relative locations.