Have had like problems with recent OEM 10 rnd. Glock mags in 9, .40 & .45. It took some of the 9mm ones months before the springs took a set. This is with them being left with as many rounds as they would hold when idle. The rounds don't even line up with the witness hols on 80% of the 9mm ones. Some of the .45's still accept only 9 rounds.
I've got the same problem. I don't think the Incredible Hulk could get 10 rounds in mine.
I wish someone would make a metal magazine
for Glocks. USA does, but I bought two of them and they both broke the first time I used them.