Key question: If you use HK OEM magazines, without any aftermarket components, do you still have the problem? If not, then just stick with the OEM magazine/configuration. If you then try the modded magazines and have issues with them, take it up with HK Parts (but until resolved and vetted, I would not use the magazines with aftermarket extensions for anything but range and gun games).
And, probably preaching to the choir to most of us, but "HK Parts" is an aftermarket provider, NOT HK or HK USA or the HK Web Store on the HK USA website.
Reality check: How often, in the real world, do you genuinely see a need for extended magazines period, as opposed to mastering magazine changes? And how often are magazine changes, other than to resolve malfunctions, actually needed?
Another potential key question to consider when going with aftermarket components with an HK (or, for that matter, any platform), is what was the quality and extent of the aftermarket manufacturer's R&D, materials used, manufacturing quality, quality control and pre- and post-market testing? With HK, you're getting a known entity, with an established track record of using high quality materials, manufacturing techniques, testing, quality control and actual fielding. I'm always wary of going with aftermarket purveyors beyond sights and grips in most cases-I'm not usually particularly interested in being a beta-tester regarding components for a weapon that's used for carry, personal defense and/or duty.
Got sent a Glock spring from Henning Group. It’s a extra power spring. Did some very slight manipulation so the spring would fit on the follower but so far locking back the slide has been extremely positive. Gonna test it with a few different bullet weights and see how it cycles. The difference between the two springs are apparent. I’m hoping there’s no issues but this mag is a rang mag so I’m not sweating it but can’t see an issue here. Hopefully I’m right.