Paint bleeding in height after slicing

[keesprinter]

I tried to fiddle around and sometimes after slicing the paint “bleeds” to another height. If you look at my screenshot you see it also in the slicer. It’s only happening in the round corners.

I painted this with the “height range” paint tool.
I tried with a different project and here it also happened with a totally different shape. Anybody got a clue?

[Neiljt]

Painting , paint (colour) can get everywhere if you are not careful enough
enlarge the image rezise the brush making sure to get the faces of the only object you need to colour

[keesprinter]

Thank you for your reply. I found the solution: toggle non-manifold edges!