Welcome to the sickness we call the CZ100. You will never recover.
How old is your CZ100? The reason I ask is that the older ones had followers without a ledge for the inner part of the slide stop to ride in. I believe the newer ones have the ledge, as do Pro Mags. I stopped using my factory mags because of similar problems.
I have also read that some pistols do not like WWB. They seem to think the rim and groove is slightly different than other brands of ammo. I have not had a problem with that ammo. My 100's have digested everything I have put in a mag. Just passing on what I have read.
I have to ask, why did you order a Glock G17 recoil spring? I discovered, some time ago, that the G19 recoil spring is a perfect fit. Have you tried the G17 spring before? Good luck with it, but before you fire your pistol with it, be sure to check and make sure that the longer spring does not prevent the slide from going all the way to the rear. You can check by removing the recoil spring from the slide assy. Replace the slide on the frame and run it all the way to the rear until the dust shield hits the frame. Mark that position and then install the G17 spring and try it again. If the slide can be retracted to the exact same position, you have a winner. If not, Get a G19 spring. Many of us have tested them and they work fine.
Anyway, good shooting. You have a fine pistol. Enjoy!
Mike