Studio One is mapping some parameters to MIDI CC. How?

We’re seeing some parameters being assigned to controllers in the Studio One automation window. But as far as I can tell, we’re not making any such assignments anywhere! And even more strangely, the parameters mapped differ between systems. On my Mac laptop and a co-worker’s PC, Master Bypass is set to CC 0. On my PC laptop, nothing is mapped. On his Mac laptop, five of the parameters show as being mapped somehow.

Is this a quirk of Studio One, or is there some code somewhere telling the host to assign these mappings? (By the way, I have added the preprocessor definition JUCE_VST3_EMULATE_MIDI_CC_WITH_PARAMETERS=0 to my JUCE project, so that all of those possible MIDI CC mappings do not show up as parameters.)