DW CCO: nosedives

[masakari]

I have a Dan Wesson CCO with Wilson Combat bulletproof slide release. I use Wilson 47OXCB 7 round magazines. The pistol has been through around 800 rounds over the course of a year, a mix of FMJ and defensive. My defensive round of choice for this pistol is currently Hornady XTP 200 grain.
When loading or reloading, I insert the magazine and hit the slide release.
My issue is this: just recently over the past month, I have started to receive nosedives in which the first round in the magazine pushes downward slightly during its forward movement, and hangs up on the feedramp base, with the bullet pushed in.
What could cause this? How come it is just now becoming an issue for me?
Thanks for any help you can provide.