What is the ruling on the bank paying an immediate amount to the investor from the expected profit in Mudarabah?

If the amount given by the bank to the owner of the capital is a debt owed by him and is not stipulated in the Mudarabah contract, then there is no objection to it. And since the Mudarabah has yielded profit, if the profit is more than the debt, the bank will pay the owner of the capital the remaining profit. If it is less, the owner of the capital will return what exceeded the profit. In case of loss, he must repay the entire debt. However, if the amount serves as a guarantee for profit, then it is usury (riba).