There are some strange things happening to my Prusa i3 MK2 since I updated firmware.
There are unreasonable layer shifting in one of print models which I successfully printed before update several times. The same GCODE file now prints strangely. Also there are layer inconsistency and wiggling with no reason. I attached few photos to explain the problem.
Black model shows layer shifting and brown model shows layer inconsistency.
To which firmware version did you update your printer?
Were both models printed on rougly the same space on your printbed?
If both models are printed after updating the firmware and you didn’t change slicer settings, it seems like this is a hardware issue.
I had the same results after the belt of my X axis was damaged. and again after the Y-belt began to deteriorate. The stepper pulley will jump a teeth and thus shifting the layers.
The original Prusa belts in my experience are not capable of handling the tension for a long time. I replaced them with kevlar reinforced belts.
So I suggest checking the belts for damage and tension.
I recently update my firmware to the most recent for my MK2. I ran the XYZ calibration then the V2, I think I also ran the calibration wizard in the new firmware… I also updated to the most recent driver package.