I know, when Bundle item is created with "Dynamic Price", then I can refund a child item. But when Bundle item is created with Fixed Price then it doesn't allow.
It looks, when order is created with Bundle item (Fixed Price), all child item's price is marked 0, which might be the case that it doesn't allow to refund a child item from it.
I would love to have this feature. To be able to refund only a child item from Bundle item (Fixed Price).