I will be glad for any help.
There are two problems.
The first is shifting layers, in absolutely random places, the only connection that I found is change of print speed in the gcode.I thought it was the layer height that mattered, but as it turned out, even on a low wide part, this defect can appear on the 10-20th layer.
The second problem is the extruder knocking down high and thin parts, even with the use of brim.
After reading reddit and the bambu forum, I carried out a full maintenance, lubricated everything, tightened all specified bolts, bed tramming, turned off “reduce infill retraction”.I don’t know what exactly affected it, but I can print tall models now. But the layers still stick out.
Today, when printing, I reached a new level of this problem, two tall parts with absolutely the same settings, but one has a defect and the other does not.
Hope someone already found the solution.
All prints on A1 Mini
Printing in PETG reveals the problem more often.
Printing in PLA also has this problem, but less pronounced.