Unwanted top/bottom-layer behavior

[maurice 1]

I recently started using Cura 5.3.0 on an M2 Mac. I noticed some new (unwanted) behavior concerning top/bottom-layers. If I print a thin section in the bottom layer, the new top-layer of that section is printed separately with walls, although the pattern is the same as in the surrounding layer:

 

The next layer shows the border of the thin section:

 

 

 

I've not noticed this behavior before, but maybe I haven't printed thin sections in the bottom part before. However, I don't want this, because it does not look good, and it creates many extra print-movements. Can I turn this behavior off?

Edited April 7, 2023 by maurice
fixed typo

[maurice 1]

I see now that the older version of Cura I  use does the same thing. I also understand why it happens this way, but it is not always desirable...

[UltimakerSV06 0]

 get this strange segment on the top of an object. In Prusaslicer its completely flat. What setting could have caused this? Cura 5.3 alpha+xmas.

 

[ahoeben 1,968]

Probably not a setting but a rounding issue with a non-flat surface. You could try slightly adjusting the layer height, or the initial layer height. Better yet: make the model truely flat on top, not "approximately flat".

[GregValiant 1,330]

Good Morning

@UltimakerSV06 that looks a lot like what is going on in This Bug Report on Github.  As @ahoeben mentioned it may be a rounding issue in the background calculations.  This problem has also been mentioned here in the forum.

[UltimakerSV06 0]

Thx for the reply.