my experience with the German immigration is that they cannot be reached by phone but personal contact and interaction where good and helpful at least where I lived
on the 24th of February there was the 400k in place have a appointment 25 April and get the letter from the bank on 24 April hopefully they will not have a problem with that as it nearly impossible to get to bank and be on time at the immigration office
sure not in The Netherlands or Germany there you need local adres registration as also tax number.
For the Netherlands I could not even give my wife access to my account as she even with tin had no fiscal binding with the Netherlands….. in Germany it was less a problem as she worked there so needed a bank account.
I’m not sure but know that the money should be in the bank 2 months before getting your extended stay permit, don’t know if can drop below the 400k, ask in this group there enough who can help