Recently I renamed an Office 365 account from a user who left the company to the user who took that position. I change the email address, the name, etc.. However AzureAD has the wrong email address under the contact information. Strangely enough, the new user receives email, sends email, nothing appears to be broken until you try to do something like share a folder in OneDrive. The folder does share to the new user, however, the person initiating the share receives an "undeliverable" email stating that the former email address (that from the original user) can't be found.
I have looked and looked and have only found the original email address in this one field. When I try to change it, a check mark appears on the right and then I click save and the email address reverts. The audit log says I successfully modified the user, but it is not actually changing.
Any thoughts? I am signed in as a global admin.