i have a curious question well i was coming from work and i start cleaning the cage then i saw one male budgie his Forehead was peeling off so im not sure that’s normal or he’s was fighting with other male budgie and here some pictures male budgie Pepe
From what I can tell, your bebe is in for a heavy molt on his face. He's gonna be super grouchy and need extra nutrition during this time to help him grow his new feathers! Read up on the stickies, and I recommend adding 1/8 tsp of chia seeds to his diet for the good omega-3 oils to help with those feathers.
I'm not familiar with your brand of bird seed, but I live in Canada and a lot of times different countries have different things so I'm not surprised. However, those black chia seeds are exactly what I was talking about! Just 1/8 of a tsp, not very much at all, will help with feather growth.
If it is a molt I would expect to see some evidence of little pin feathers poking out of the bald spot, I don't see any in the picture are there any there? Is he rubbing his head on anything persistently?
From what I can see, that does not look like a molt.
I believe your budgie has been plucked by one of your other birds.
Can you post a full sized picture of the area on his head rather than a thumbnail?