When the door is closed, after some time printing process is stopped and the head starts finding zero position, after that goes to the start position of g-code, stays some time there, again zeroing, again to start position and so on.

I blamed the feeding mechanism, but the stepper is not hot, so the filament goes to the head untouched.

This printer has no error codes, or I have no knowledge to see them, so I can't say for sure is filament guilty for this or just the printer loses current position.

If this matter, I'm printing only from SD.

Tried to print with removed left panel, to arrange good cooling, and with closed door, the problem persist.

Any idea?