Here's a video I took of the issue:
The trigger has a thin piece of plastic that moves behind the bumper and I assume it's to prevent things from getting lodged in between them. However, because the bumper has so much wiggle room, it actually collides with that piece on the trigger if I try to pull the trigger when holding down the bumper.
I know that I could probably remap the buttons to flip them and be holding down the trigger while pressing the bumper, but that's not really the point.
Buttons physically interfering with each other seems like a problem that shouldn't happen in the first place.
I don't suppose there's anything that can be done about it aside from remapping or trimming those little guard pieces off the triggers (which I don't really want to do)?