My oldest son suddenly began experiencing FTE(xtract) with his G43 X MOS a while back. I tried to troubleshoot it over the phone and by video (he lives in Maryland, I live in Texas), but no joy. I suggested that he either find a local Glock armorer or gunsmith, or return it to the mother ship. He took it to a local gunsmith who quickly diagnosed the problem as an over-length red dot mounting screw that was binding on the ejector plunger. I don't know all of the details, but the gunsmith removed the red dot and the gun functions now. My son is now in the market for at least one shorter screw. Or a file. Sometimes it's the easy things that you overlook that are causing the problems!