We have a number of trees (I do not know what types) and this tree is the Asian cooking banana. Called sugar banana and can be cooked without the fruit falling apart.

The last couple of years, the trees have been producing fruit that have blackish rough marks on the skin and the fruit has had lumpy flesh. This is the case even with the fruit in the hand that has hardly any of the rough blackish marks.

Any ideas on what this could be?