Error occured if required fields for 1 user types is not necessary in other user type

I used user types to create Individual & Team user type. I assign profile field birthday to Individual user type and set it as required field. When Team user edit their profile, they won't see the birthday field which is correct. However, when they submit their profile page, error dispaly showing that 'The field Birthday is required'. Appreciate anyone can help me to solve this problem. Thanks in advance.