Having to try different brass is preposterous... definitely a problem there, and it certainly sounds like the spring/extractor is a culprit... well, that and poor QC all the way round.
New products to market usually have some issues... but this ought not be. It's a fairly simple mechanism and the father (NULA) has been around for a couple decades.
Shameful...
“Perfection is Achieved Not When There Is Nothing More to Add, But When There Is Nothing Left to Take Away” Antoine de Saint-Exupery
