It really common for babies to get issues and at this age I think their immunity is changing.
Birds hide being sick , until they can't hide it any more because they are so sick . It's instinctual it's not like they are choosing to be tough. So any symptoms should be taken seriously and always err on the side of caution .
It's so much easier , cheaper and better outcomes if health issues are caught early. What we think of as "typical" sick bird symptoms are actually serious or critically ill birds. When they reach the fkuff d nit eating stage they are often 48 hours or less from death
Hand fed babies can easily aspirate and have a little sinus infection or respiratory infection going on. It could be something like avian clymadia a relatively common bacteria infection or birds . These this of things can be treated and resolved.
I myself wouldn't risk it, I would consult an avian veterinarian, I'm going to share decades with my parrots , it's worth it to me spend a little money to be sure, or to take care of it before it becomes more serious.