I have a 21 limited GCL and have had many of the same electrical problems as many others on this forum including auxiliary battery drain causing start/stop to not work. Had recalls and updates done, dealer techs investigated to no avail and then computer completely wigged out one day. Master tech was puzzled and was gonna open a STAR case but did a “deep dive” first and found a blown multi function fuse that he believed had been cracked earlier. Replaced it and to date, everything is functioning well, not perfectly yet but well. Part #68498509AA. Hoping that may help others out there.