Is Zakat obligatory on two investment accounts in an Islamic bank, given the dispute concerning each of them?

Both accounts are zakat-eligible together if one is a profit for the other, and that is upon the completion of a hawl (lunar year) on the first nisaab (minimum threshold) that was completed from them. However, if each account is independent, then what has not reached the nisaab is added to the account that has reached the nisaab, and both are subjected to zakat upon the completion of the hawl of the first account, or each account is subjected to zakat upon the completion of its own hawl.