Fill between slices, makes troubles!

So here we see the segmenatin before the “fill between slices” and after I applied “fill between the slices”

IT appears to me that this does not only fill the empty slices that were not segmented, but instead changes the shape of already painted segmentation of slices.

How does it do so? What is the logic behind this?

If the slice has already been segmented, and the slice above and the slice above. Why does this function change them if it says "fill BETWEEN slices?

I assume it would fill an empty slice between the two existing segmentations of slices, not change the two existing ones?? Am I wrong?

How does it work?

I wonder if this is somewhat related to the previous discussion about slice increments?

“Fill between slices” effect fills between parallel slices (along any of the 3 axes). See detailed description of the algorithm here.

Any editing operation in the Segment Editor will resample all the segments to the common labelmap geometry. If you have just imported a segment from another segmentation that had different geometry (higher resolution, different origin, or axis directions) then the segment will change upon the first editing operation. Segments are not immediately forced to the common image geometry to allow lossless moving/copying of segments between segmentations.