This can be caused by diet missing critical minerals, problems with the thyroid, skin diseases etc.
This paper in PDF format lists a lot of the issues
abvp.atiba.com/site/omnipress/papers/A4.pdf
I would suggest seeing an avian vet for a check up for this bird. You can find one by checking with local vets or this website may help you locate a good one in your area
www.aav.org/vet-lookup
I do think its something you need to address as its likely a symptom of more serious problems.
Hope this helps you!
Please press Accept if you find my answer helpful. Want more info? Just reply on your question!
Bonuses for good work are always appreciated!
Thanks for the opportunity to help you!