MXAO and Depth Buffer

I have never used MXAO before but this particular game (Subnautica) has HORRIBLE banding if yo use the in game SSAO so I thought I would give it a try.

Toggled it, nothing happened so I loaded up DepthBuffer and notice I just get solid blue/white scree.

Does this mean this game doesn't have an accesible depth buffer so I am out of luck?

Other option: Use ingame SSAO and reshade deband effect