الجواب حامدا و مصلیا
Of the requisites of any Mudharabah contract is that if there is a loss, it should firstly be fulfilled from the profit, and if it cannot be fulfilled from the profit (i.e. the loss is more than the profit), then the loss will be borne by the Rabul Mal (Investor), not the Mudharib (entrepreneur). For this reason, it will not be permissible to exchange the stipulated ratios if there is a loss, as mentioned in the inquired about scenario. However, after fulfilling the loss from the attained profit, whatever remains of the profit will then be shared between the Rabul Mal (Investor) and the Mudharib (entrepreneur) based on their stipulated ratio.