I had the same symptoms as you, I posted a comprehensive walkthrough on this forum that I guess was deleted like many others. Sent message to moderators, no answer.
Briefly, one cell was problematic so they changed the rear (biggest) cell group. Worked for a week, problem reoccurred. They changed the BECM good for a week. Then they soldered some x358 pins directly, then changed the HPCM2. Took 5 visits and maybe two months.
Working since. 4 months.
