Is it obligatory to pay the interest accrued on a current account that has become negative due to the bank imposing monthly interest and fees, given that I no longer reside in the country where the bank is located and the account did not originate from a loan?

There is no objection to the bank charging fees for current account services, and there is no suspicion of usury in this, because in this case the bank is a debtor, not a creditor. Demand deposits (current accounts) are considered loans from a jurisprudential perspective. The customer must close the account or pay the agreed-upon fees. The fact that the customer is a non-resident does not affect this, as they can appoint someone else or contact the bank to close the account.