Help! Really weird ender 3 problem

[Roberts_Clif]

This is called layer shifting.

It is caused by a few mechanical adjustments or sticky grease on your smooth rods.
XY axis belts too loose or too tight, V-Ref current incorrectly adjusted. Bad stepper motor highly unlikely though possible.

Smooth rods work best with a light machine oil rather than any kind of sticky grease, the smooth rod bearings have never been cleaned with the factor packing grease.

Great Bearing Cleaning video

White Grease like Vasoline can cause smooth rod linear bearing movement problems.