CR-10 SE - strange 'stripes' thickening parts of the model

I have a strange issue with my CR 10 SE I bought about 5 months ago as my old CR-10 reached its end and since then have been extremely happy with. Every print came out faster and gorgeous.

Last month, when I wanted to print a mouthpiece for a PVC flute, the prints had strange stripes in them inside and outside. Interestingly exactly at the same height for THAT print.
Problem is that it’s not always at that height. Yesterday, I printed different test models and they had the same problem at another height, but all prints in that session at the same height.

The bigger the model I print, the broader those stripes.
The pictures show the mouthpiece I printed with additional thin stripes on top and the test models I printed including inside views.

Do you have any idea how this is possible?
I also tried to use another slicer than Creality Print but don’t have CR-10 SE profiles for it.

Thank you.



I am sure this has already been considered but, are having any z-axis binding of any kind? Just a thought.