Stageshoot
Banned
I think the preheat checks cp/pp signalling to check if charging is active before using battery power. When plugged in it must be seeing the signalling as non active and errors instead of using battery power..all theory. When an active charge is discovered life is hunky dory
This is exactly the problem the Kia EV6 had took them a year to fix it, and even then there are were issues.. Nobody had Cabin Pre Heating for the first year, which was a real pain..