Is it just me? I've got about 600 rounds through a new CW 45 now and the problem is getting worse, not better.

At least once each clip, sometimes twice or trice, the slide stop moves a little to the left. If it moves over to just the right spot, the slide locks open. If it goes a little further, it just hangs there, sticking out of the left side of the frame.

WTF is going on here? This is my daily carry pistol, but not for long unless I can get this handled.

Any ideas? Am I doing something wrong during reassembly? The stop appears to be seated correctly.