Why is my controller in turbo mode?

[AortaPlatinum]

I'm using Valve's official motion control controller bindings with my Switch Pro Controller for HL2 Ep1, but some of the inputs are weird. When I hold or even just tap a button, it seems to register an input every frame, like I'm mashing the button like crazy. Closest comparison is the turbo function on older third-party console controllers. It only effects the shoulder bumpers, the stick clicks, and the dpad, so I got through the Citadel but I don't think I can finish the rest of the game with this issue plaguing me.