What brand of magazines are you using?
The reason I ask is MagPul PMags swell when fully loaded and that has caused them to not drop free and also be harder to fully seat in my Gen 3 Glocks and Polymer 80 builds.
I have never had any issues with oem glock mags in my 19 and all three dagger frames. Of the five pmags I have, only three have been loaded for 6+ months and don't drop free from my FDE frame but do for both my two black dagger frames and 3d frame. could be a psa frame issue. Glock mag does drop free from FDE frame. Range use, yes mapgul but carry, oem.