Assuming there is no 'limp wristing' issue, does it have problems with all 4 mags? That might indicate the problem is with the magazine catch holding mags too low. If so, you should send it back. If not, I suggest you put a piece of masking tape on each magazine body or floorplate, label them #1 thru #4, and sort out the offender(s). Bad ones may have an issue (bad batch) with position of the catch cutout. Send them back.
Given it's intended purpose, you need 100% reliabilty.