

There’s two kinds of haptics with the trackpads, one is haptic feedback when using the trackpad, the other is simulating controller rumble using the trackpad haptic feedback.
I’m guessing it’s one of these two causing the vibration. you can individually disable them by pressing the QAM button (the “. . .” button), going to the gear menu, and scrolling down to the bottom where there should be toggles for game rumble and steam haptics.
I also might try switching to a different control profile and see if it still happens. Ideally a pretty blank profile where the left stick is configured to let you move and that’s it.
Ok, I missed that changing controller profiles fixed it.
I’d still recommend trying the global toggles, that will let us know whether it’s haptic feedback or simulated rumble. From there we can hopefully narrow down what’s going on with the control scheme.