A late update with my device suffering this issue...I fixed it after tightening a loose screw.
I dissembled my phone looking for any loose connectors, specifically the flex cable to the USB sub board, but the screw circled in red was loose with maybe 1mm of movement between the screwhead and PCB. (thanks to @gelraen.ua for the photo, I forgot to take photos haha)
The FCC teardown photo below shows some contacts on the underside of this PCB. So my theory - without knowledge of the schematics or circuit diagrams - is that a lack of contact against the metal midframe caused the Hal