The CZ82 SHOULD handle any brand of ammo.....not a problem.
Low grouping shots could be from your sight picture,or could be corrected by alittle filing on front sight. It's basically a close range weapon. Practice.
NOW.....my safeties are a little hard to engage, yours could be loose. I suspect you could be limp wristing...ie...not holding the pistol with stiff wrists allowing it to roll. This can cause the thumb to force the safety up and halt firing.
Try some more shooting, but be conscious of your grip.If it continues to fail...then see a smith to fix it.
Mainly, get used to this little powerhouse and I think you'll be relieved. ALSO.....when you look down the barrel......you will NOT see lands and grooves. The CZ82 has polygonal barreling.....looks smoothebore.Enjoy your CZ.