C2 3000 Round Maintenance

I have shot 3000 rounds through my C2 and it’s a dream. With regular relubrication and basic wipe downs it has handled flawlessly. Just in the last 500 rounds or so I have noticed that my Staccato mags are not locking back to the rear after the last shots on the magazine. In addition, I had my first failure to eject when I was nearing round 3000.

Is there any additional maintenance to be conducting with this round count and magazine/ slide locking to the rear challenge?