I made the retard error like most men do, and ordered a bunch of plumbing supplies off eBay to put in a new water main from the street.
Luckily, everything but the PEX-B stainless steel crimp rings were good, and performed/installed fine. They were $12 for 50 of them, and I should have known it was too good to be true. The Apollo brand was $8.50 for 10. Quite a price difference, but there’s a huge difference between the products. The Apollo is about twice the size (in thickness) as the Chinesium ones, and crimps very well.
What was happening: I’d go to crimp the crappy one, and as I got it tight enough, the ring would snap off, or it would leak.
I did about 20 rings before I said ‘f- this’ and coughed up the dough for the name brand ones. Worth it: every single one went on without a problem.