Like my uncle, an old car mechanic used to say, "Check the cheap stuff first." Try wiping your mags down with a silicon cloth first and see what happens.
Second, put an empty mag in, turn the gun upside down and press the release button. If the magazine doesn't do about a 1/16 -1/8" jump than it might be time to try at least one new mag spring to see if that's the problem.
Sometimes a magazine spring will get just weak enough, combined with some grit inside of the top of the mag that the mag won't drop.
Non-dropping mags is also a good sign to change your springs. The next step in a weak mag spring is a FTL. Don't want that in a "aw s**t!" situation now, do we?
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Our department's range weapons started to show these flaws on our H&K's. Dirty mags and weakened mag springs were the culprits. Our H&K's have seen years of service and thousands of rounds through them. But keep in mind, when not in use, all of our mags are stored empty. The mags on your Gen 2 have probably been stored fully loaded for almost as long as ours so I would suggest it might be time to invest in new springs.