newly grown feather just molted??

[Ezekiell]

I was super excited because over the past month or so Māui has grown a pair of new flight feathers. But this morning, he just dropped one of the newly grown in feathers.

I’m super confused. Is it normal to grow a brand new feather then after a month have it drop out?
The feather isn’t damaged in any way and he doesn’t pluck. My partner was with him when it just dropped out after he flapped his wings. He has a good diet with lots of fresh vegies and fruits, with nuts as foraging treats only. Medically, he’s clear of any diseases that could cause feather loss.

I’m looking for reassurance, because I didn’t think this was a normal thing to happen to a brand new feather.