I’m not sure if this is a bug or if I have a setting set wrong somewhere? I thought I used to be able to set support top z distance and bottom z distance independently of each other but it seems as though whatever support type I use, if I set the top z distance to something the bottom z distance reflects the same setting when sliced even though it differs in the settings. See in the screenshot where I have top z set to .2 and bottom set to 0. This should mean that the bottom part of the support prints directly on the model, instead it prints in the air. The green support layer is printed along side the top layer I have pointed out.
If I set Top Z distance to 0, you can see the bottom z distance also reflects this in the sliced model.
Same thing if I set the bottom z to .2 and the top to 0, it still reflects the setting of the top z setting in the sliced file.
Untick the box for top and bottom distance being the same 
Maybe I’m blind? I don’t see that tick box anywhere. Unless you are referring to the “Toper Interface Layers” and “Bottom Interface Layers” dropdown which allows you to choose “Same as top” or “Same as bottom”. I’ve set both of those to varying options such as “0” and “0”, “0” and “2” etc. If that is what you mean and there is no other tick box, could the issue be because it is printing on top of the model to support another part of the model rather than the supports starting from the build plate?
Ahh, I think I see the issue now…
I did not pay enough attention to your pics.
I wrongly assumed you meant the interference layers.
I tried to replicate the problem and found that you require a minimum distance between parts/plate in order for those distance settings to work as planned.
If the gap between parts/plate is smaller than the sum of the support setting for base and such it all gets messy.
In my test it worked best using standard supports with the snug box ticked.
But for complex models with little space I can still get the same problem you have.
In some cases though the bridging capabilities might be enough and a few manual supports or none at all do the trick.
