The issues are on the dec axis. It looks like a large backlash with some stiction. Check the gear mesh on the dec axis.
In addition the calibration is suspect although that is not causing your problems. But it could indicate something going on. Every second calibration step is almost adjacent to the one before. That is on both axes.
You've also got quite a big drift on your dec axis. Could be poor PA or flexure from a loose fitting somewhere
edited to add:
A photo of your rig may shed some clues
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