1 of the 3 mags doesn't hold the slide back after last round about 50% of the time. I'll clean my gun then try again. If it continues to be a problem I'll contact Glock.

I bought 4 10 rounders about 2 years ago. 1 of them had the same issue with holding the slide back. Glock replaced it and all was good. I have concern about Glock's QA on the lower capacity mags.