Issues with phantom scrolling when using steam and quick access button

Hi all,

I've got a steam deck that started having problems a few days ago. When pressing either the steam or quick access (...) button, it will begin scrolling to the right and continue past the end of the scroll (you hear the sound it makes when theres nowhere to scroll to) until the b button is pressed.

The only diagnostic efforts I've made so far is removing both button boards, both touchpads, analog sticks, and all buttons associated. I cleaned the non electrical components with soapy water, and the electrical components with 91% IPA. Shows the same issues after reassembly.

I have not observed any damage to the internals, liquid or otherwise. Thanks in advance for any insights or advice!