Just made the leap from Nintendo Switch to PC (these graphics holy-moly

), and I'm playing via Steam with my Switch Pro controller, which Steam supports. The buttons in the game display in the XBox layout, which is a minor annoyance but no biggie, but what I'm mostly wondering:
With an XBox controller, is it really the case that in menus, A = Select and B = Back/Cancel? On the Switch versions of past 2ks, it's been the opposite (well, technically the same letters, but opposite positioning since Nintendo controllers go B A instead Xbox's A B).
I just want to make sure there's nothing screwy going on with the button mapping. If indeed the buttons are just opposite on XBox (lower left button = Select; lower right button = Back/Cancel), does anyone know if there's a way to edit that keymapping purely for menus, or is it always the case that the Pass Button must be the Select button and Bounce Pass must be Back/Cancel?
Many thanks, folks.