Nico1704 At bunq, there's no "main account". All sub-accounts are equal. You can delete all sub-accounts and create new ones, they all work the same. What you think is your "main account" is just another sub-account (all accounts are called "sub-account" at bunq).
I believe some German banks don't support payments to bunq sub-accounts that have been created in the last month. You'll have to wait one month until you can transfer money to these sub-accounts.