and you said that there was a moment when both lights, left and right were on?

going from simple to more complicated, I would troubleshoot the xenon light bulb - (some of them you already have completed)

pull the bulb from the "defective" location and put it into the operating location - if problem moved, problem is with the bulb, if problem remained on the drivers side,

i would pull the ballast from "defective" side and try it out in the operating side - if the problem moved, problem is with the ballast, if the problem remained, then

I would try to source BMW software, or get a mechanic who has BMW software, such as GT1 or INPA and read the status of the LCM

since there are NO fuses protecting the light bulbs, you might have one of the MOSFET transistors gone bad, which will call either for a new (used?) LCM or a repair to existing one... the LCM troubleshooting is more involved thus lets hope that the problem is with the light or the ballast...