Any pictures of groups, where it was “tack driving” and then shifted?
Are the turret screws tightened?
2+ years dealing with a scope that may not hold zero or track? Most would only wait a week or two to figure out the problem. Were you shooting it much during this time?
Did you zero, then adjust the scope up/down 5+ mil in both directions to see if it would track?
I know Vortex has a reputation by some as needing warranty work, and it’s typically from the lower end stuff, but having 7+ Razors (Gen 1, 2, 3), 3 AMG’s, 4-5 PST’s of various Gens and a 5-25Venom, I’ve yet to send one back for warranty work. These have been on AR-10’s, 260/6.5’s/6creed bolt guns and a few magnums (not the Venom) with thousands of rounds fired among them.
Maybe I’ve just been lucky, but if they were as bad as some would have you believe, they wouldn’t still be in business with repeat customers. Odds are your replacement will be fine and this may have been an anomaly.