axis shifting problems

I had a makergear prusa i have the problem whic you can see in pictures (it's a bullet print try) don't look at the middle where one layer are discontinued it's another problem on the extruder and i'm working on it. I don't understand why that shift in the first part and at the top
Advice?

It looks to me that you have not set the current on the stepper drivers and the steppers are loosing steps.
This can cause the effect that the photos show.
Also the extruder stepper driver may also have the same problem which will make a loss of extrusion causing breaks in the layers.

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I had the exact issue with my y axis. Upped the vref and problem solved