Glock also updated their 10 round mags. You may try picking up the latest gen Glock OEM 10 rounders (with orange followers) to see if things improve.
The best way to fix your issue is to take a day trip to Arizona, Oregun, or Nevada.
Quick update.
Since my original post I've been using OEM mags and have fired 800 (+/-) trouble-free rounds.
Last week I went back to Magpul mags for one session, and had a failure to feed. During that same session I also dropped a partially loaded Magpul mag on the ground, and the follower got stuck halfway down the mag body.
OEM mags for the win. Thanks for the input folks.
The number one issue with magazine fed weapons is…magazines - me.
#RESIST
For the record, my bet was on a slightly too long optic plate screw on the extractor channel side interfering with the extractor plunger. If the problem crops up again remove the plate as a test.
You don't need to remove the plate and go test it, just check if plunger can be removed... Too long of a screw will pinch the spring in place. You can also look inside the channel with a flashlight upon initial installation, if you have first removed the plunger spring... Too long of a screw will show through inside.
I agree with others that the Magpul magazines would be the first thing to look out. The feed lips wear out and have a limited lifespan. I have four and end up returning one or two to the factory every so often. New and for the first year or two they work great.