AVToolButtonSetComputeVisibleProc sets the enabled state of the button

I have an add-in that adds a toolbar to acrobat. This toolbar contains 3 buttons. Based on the active document, some of these buttons should be visible, and others should not be.

When I add the button to the toolbar I am using the AVToolButtonSetCompteVisibleProc function to set my visible callback. In a very simple example I have set my callback to simply return false. When debugging the code, I can see that this callback is called, however the effect is that the button is disabled, not hidden.

The version of acrobat is Acrobat Pro DC Version 2018.011.20063