My XC40 2019/2020 is dead. No electrical power at all. It happened 2 months after the purchase in last December, and some months later again. These times it revived by itself after some hours. All the sudden the car gained electrical power and I could start the car But this time, no revive. Total black-out. The Car is now in a Volvo garage, for a week by now, but mechanics are unable to find the cause of problem. No diagnostic can be run because the car is all off, maybe. Can anyone tell what it could be?