Do baby African Greys fall asleep standing up and is it good or bad?

Very young baby birds don't have enough leg strength or co-ordination to stand up for very long.

A bird that's old enough to leave its parents is going to spend most of the rest of its life standing, even when sleeping. In most cases, if a bird is old enough to have left the nest, and you see it lying down, it is probably critically sick or injured and needs medical attention right away.