Unfortunately I've had it happen. Re-zero the scope and shoot enough rounds you are confident it will hold zero. It will either hold zero or it won't. I will say the few incidents I've had, my scopes are still working good.
"All that is necessary for the triumph of evil is that good men do nothing" Edmund Burke
Browning High Power,XD 45, Protec 25,Saiga 308
Stag AR 15, Ruger mk II 7mm Mag, CCW