Slicing missing an interface layer

Bambu Lab Software
1

Hi all, I have an issue where the slicer (Bambu Lab) misses a layer for my manual interface layer.

CAD:

Screenshot 2024-02-09 at 13.31.54
Screenshot 2024-02-09 at 13.31.541920×1222 145 KB

Screenshot 2024-02-09 at 13.34.02
Screenshot 2024-02-09 at 13.34.021920×919 188 KB

Slicing:

Screenshot 2024-02-09 at 13.38.30
Screenshot 2024-02-09 at 13.38.301920×1241 216 KB

Screenshot 2024-02-09 at 13.38.38
Screenshot 2024-02-09 at 13.38.381920×1241 216 KB

Screenshot 2024-02-09 at 13.38.49
Screenshot 2024-02-09 at 13.38.491920×1241 214 KB

So the interface (black) should start on layer 8, instead it starts layer 9.

Any thoughts?

I have reprinted this failed print so many times trying to track down the cause :S

2

FYI, adaptive layers fixes this, as does moving overlapping the interface with the bottom part.