Slicer not generating bottom support interfaces

I am trying to dial in my settings before a big print and I am using this stl to calibrate my settings: Customizable 3D printer support test by zapta - Thingiverse

^ This is the model (so you don’t have to bother to open the link)

^ This is the model created in the slicer with just the support interfaces visible, note how support interfaces are only generated for the top.

^ And when we look at the cross section we see the printer makes the support out of the same filament as the object filament, and places this support directly on top of the object.

I am attempting to get the first 1-2 loops of the tree support that are created on top of the object to be made of support filament (not the entire support itself) so that it doesn’t bind and scuff up the surface of the object. I have tried a bunch of settings in the Support tab and none seem to make the slicer create a bottom interface layer.

To further reiterate or clarify the issue if I have been bad a communicating it:

^ the ideal scenario

It seems to be an issue with “Tree (auto)” as “Default (auto)” support type does generate bottom supports. I would like to try and get “Tree (auto)” to generate this bottom support so I will keep the post up.

I have also experienced Bambu studio not generating supports in some areas and sometimes none at all when using auto.