Post up what CZC says and if it is fixed.
We need a little more information to be better able to help you solve the feeding issue. Does it hang up on the ramp (nose dive)? Does it hang up nearly fully into battery? What brand/type of ammo are you using (specifically) or are you reloading? Did the issue happen all of the sudden or has it progressively gotten worse? Are you having any extraction issues as well?
The main causes of feeding issues in a 9mm CZ are (in no particular order):
Ammunition doesn't fit in chamber. Either it is loaded too long and the bullet ogive profile is too blunt and engages the barrel rifling before headspacing properly on the case mouth or there is some bulging issue with the cartridge case due to crooked bullet seating/seating depth too deep. A "Plunk Test" (google it) will determine if your ammo is suspect.
Extractor is dirty. Crud build up under the extractor prevents the next cartridge from sliding up the breech face and causes the feeding issues. Generally you should clean under extractor and channel frequently and leave it dry or use a dry lube. Also you could have a burr on the breech face or extractor that is causing a hang up.
Magazine springs are weak or feed lips need adjustment. Over time the springs will loose there force and not provide enough force to adequately position the nose of the bullet upward during feeding. If you have modified magazines that let you load more than the rated capacity (grams followers, extended mag bases, etc...) you can actually flare open the magazine lips and that can cause issues over time as well. I have found during magazine maintenance that I need to measure the feed lips and adjust them on occasion. I stopped trying to force extra rounds in them even though some will take extra and still work. On magazine maintenance, I have found that waxing the magazine tube inside and out will help tremendously in both keeping them clean but also loading them. It also helps them function well too. I use whatever carwax I have on hand and polish them just like waxing a car (wax on/wax off).
Feed ramp is dirty/has some damage. I found that I had a burr on the edge of one of my competition gun feed ramps. I have no idea how it became but I stoned it off and polished the ramp again. I generally do polish feed ramps as it is easy and eliminates that as a concern. A drill, felt bob, and polish is all that is needed to make it happen.
Recoil spring is weak. This is not generally on my radar but I guess it could cause failures to feed if you are running a really light spring. You run the risk of damaging slide stops running really light with normal power ammunition. 11 lb recoil springs are a favorite for USPSA minor loads so I don't think that is your problem.
Good luck! We are here to help if enough detail about the problem is provided.
Cheers,
Toby