Update - was hoping it the issue in the threads below. Low pressure fuel line sensor leaking into connector X20008 and shorting there, or making its way to the DDE.

https://www.xbimmers.com/forums/show....php?t=1790240
https://f30.bimmerpost.com/forums/sh....php?t=1791502

Turns out this wasn't this issue and it's actually a faulty DDE. Will report back when the DDE is replaced.