I have a Maxus that will fire and cycle perfectly, but after one or two shots, the forearm moves slightly forward, causing the latch (lever) to open slightly. The next shot, the forearm comes completely off. I have replaced the spring retainer, where the latch hooks into, but it continues. I can't find any similar complaints on my forum searches, so I'm asking has anyone experienced this, If so, what will fix it? I've had 2 local gunsmiths look, but they can't seem to figure it out.