*** OFF TOPIC***
I have always used WWB for my 9mm and .40S&W. I have had only 1 failure for the rounds to load compleley into the chamber for my XD40Sub-C.
(I now have 900 rounds through my XD, using WWB 100 round value packs, with that 1 failure at around round 80)
I have about 300 or so rounds in my Hi-Point using WWB 100 round value packs, failures were due to the nose of the round pointing down instead of up, its a magazine problem not ammo.
I also have 200 rounds through my CZ75 Compact, again using WWB value packs.
**Ok, back to the topic**
I would talk to a couple of veteran CZ owners, czforums.com is kind of slow to respond, but their are dedicated people to this particular firearm over there.
Sounds like a new extractor with wolf spring seems to be the main suggestion. I would call CZ to see what they say.