It is not your issue to fix - it is their responsibility.
However, after many of these, I find the mag well rail lower edges to be very, very sharp, and they may be grabbing and cutting into the soft brass, thereby holding it a bit too long and not allowing the round to pop out normally and into the extractor as it should.
Look at your trial brass - do they have sharp slices on them length wise?
If so, you MAY (if you are confident as it will harm your warranty) use a fine fine emery cloth to SLIGHTLY dull those lower mag well edges.
Be careful. As I said, it is not your responsibility to make it work correctly.