Juvenile Moult

My young budge has just been going through his juvenile moult. His moult has gone fine but too long new tail feathers dropped out. the feathers started emerging from the end of the long keratin sheath but the sheath failed to come off and the feathers were discarded. Is there something wrong. He seems very healthy. Very bouncy and chatters all day. I keep him with a hen of about the same age. her moult has been fine.