It could be a loose connection or driver set wrong. If one wire is loose you will get that bad stepping. If you want to check the pot, If you are using my board, my driver, my power supply, my steppers, the voltage for the x and y should read about .7V.
I had some issues with one of my MPCNC’s last night and it turned out I dropped a spool on it and it yanked the wires and made a bad connection on the far Y axis motor. reconnected it and working great. I was getting layers randomly shifting on my printers and you could hear the motor kind of grinding randomly.
Are all your bolts loose, this could also be everything over tight, putting too much drag on the steppers? It should be much more loose than most people expect. I have people trying to return printed parts because they literally crush them with the bolts.