There is an ongoing X-axis shift in almost all layers. What is the reason?

I had that on my Y axis of an Ender 5+ when the filament was getting snagged up. Could something be snagging on the X axis?

As far as I can understand, it moves quite smoothly along the x-axis

Double check that your belts on your printer are not loose or too tight, you want them to be pluckable with your finger but not too loose or too tight as it could cause skipping.