to the op:
the thing is, you will need to switch some parts around and see which one works.
Some pople fixed the problem changing the recoild spring, some the extractor, some the ejector. Glock has different parts of each for the same gun and they are all numbered differently, so finding a combo that works, might be frustrating.
I would recommend getting apex parts that are high quality machined parts. I don't think the recoil spring will solve anything, but since you are getting parts get a new one too.
Go on youtube and google gen 4 brass to the face and you will see. The conversation is real, and the problem existed, there was never a real solution for this issue except for changing parts around.
Try Brownells for all of the parts.
over and out.
Cheers.