Banding issue?

Hello all!
First off- great printer! love it!
But… I’m having this banding problem where an inch wide section of the model seem to shift over about 1mm.
Anybody know whats going on? Is it a calibration problem? I even tried to put it on the floor to minimize vibration.no luck.
Using the latest Cura on mac and pc.
Any help is appreciated.
thanks
Kenny