Why do my user have @azuread domain instead @mycompany

Question

Hi,

I have a Windows 11 laptop joined to mycompany's Azure AD domain. When a colleague logs in with name.surname@mycomany everything's ok. However, when we tried to do some stuff, we noticed that Windows sees that user by namesurname@azuread. The problem occurs, that we have non-english alphabet, and our names in most cases have have non-english letters (like ć, š, ž, đ), and the username@azuread will not use name.suraname from UPN, but will join user's display name from Azure and with that namesurname will have non-english letter that produces many problems with our internal services.

Is there a way to change that behaviour in Azure AD/Entra?

Thank you,
Best regards