Power A wireless GameCube controller--can't soft-press R

[stardustandsunshine]

I'm using Steam to access Dolphin and I can play Super Mario Sunshine just fine with my Power A Wireless Gamecube controller (the one made for the Nintendo Switch, not an old Wavebird), except that I can't lightly press R to spray water while running. It only works when I press the button all the way down. I Googled for solutions and I have both "R" and "R-Analog" mapped to the "Trigger R" button, and I've adjusted the threshold from the default 90 down to 75, 50, and even 30, with no improvement. Just to make sure it wasn't a controller-specific problem, I tried it with the Switch Pro Controller also, and it didn't work with that one, either. So is it possible that both controllers don't have the ability to only partially press the R button, or have I got something set wrong?

It's working fine otherwise, so far. I'm fairly clueless about this, so please explain like I'm 5. Thanks!

[ExtremeDude2]

I don't think any of those controllers have analog triggers.