Don't cut any springs just yet. Failure to extract may be a result of lower powder load or too strong a recoil spring amongst other influences. Failure to feed could be a result of too weak a recoil spring, oversize ammo, bad mag etc. You don't want to cut a spring down because it's not chambering the ammo fully.
Remove the barrel from your pistol and grab some of the ammo, esp the ones that causes the issues if you set those aside. Drop the ammo into the chamber. Does it drop in freely and sit in the chamber properly or does it stick out a little? If you invert the barrel, does the ammo fall out on its own weight or very light shake/tap or do you have to pull it out with your fingers with some light force?
If it doesn't seat properly with some ease and you need some force to push it into the chamber fully, your ammo is at fault. Ammo shot from an unsupported breech or loose chamber will get fire-formed to that chamber and when the spent cases are resized, they may not resize all the way to the rim hence why they get held up back there. More prone are the cases fired from unsupported chambers.
I believe the CZ barrels are pretty tight chambered and I've had to run the ammo through a carbide factory crimp die to resize them for my buddy.