First layer incomplete when printing upside down

[jeffminton]

when slicing upside down (with the tops of the hooks facing down) it appears that some of the model is not flush with the build plate. I have noticed when looking at the tool path that the front of the holes and the first layer of the hooks are not being printed.

I have uploaded two screenshots from cura. The first shows the model in the orientation I am slicing it. The second shows the path of the first layer of the print where the parts I mention are seen to be missing.

I am using cura 4.6.1.

[MGX3D]

Can you share the parameters used? Note not all variants can be printed without supports, especially the ones that are angled (it's not possible to have both the pins and the top of the object in the same plane).