I have been printing for a few years now, and recently purchased an Ender 3 S1. I have a strange issue, that I couldn't resolve yet.
If there is a geometric change between layers, then the unchanged parts misalign also. I attach a picture, but try to explain too: A flat vertical wall is looking perfect, but if there is a window in it, the rest of the wall is displaced in the same layers at the bottom and top of the window, then resumes normally. The error is in connection with the object's geometry, not the parameters of the printer. (It is not at a specific Z height) In a calibration cube, this happens at the bottom and top of the Y and X letter indents.
So, I checked the belt tensions, rods are straight, nothing loose, nothing too tight, and the temperatures are steady. I tried 20 mm/s and 50 mm/s, the same result. Not a layer shift, everything else is spot on position. I'm thinking of a slicing issue maybe? Or over/under extrusion? Really out of ideas.