I have the following problem.
The print bed was very deep on the front left. With the tutorial from Creality, I realigned it and had an almost horizontal print bed.
After two days and about 10 hours of printing, new autoleveling. Now the front left side was again extremely lower than the right side.



Switched off the printer and turned the left Z-axis threaded spindle by hand. The picture show the result.
Now printing hours and the bed level change.



This picture show after 4 hours printing, bed level change. always on left side after runing Autolevel.



In this picture you see left is turning, but the right side not.Strangely, only the left spindle adjusted the height of the bed, the right and rear Z-axis spindles did not rotate.



This picture show correct way.
When I turned the right Z-axis spindle, all three spindles turned.

How can I remedy the fact that the position of the print bed keeps changing after a while?

I have make a video, about the turns, but not possibe to show here.

K1C, bed level change