Trying to change user's name. Change to email address is being reversed in AD.

Hi there,

I'm in a hybrid Exchange deployment with Exchange 2013 and Exchange Online. This user's mailbox is hosted online.

In AD I am changing all instances of their name from "First LastA" to "First LastB" including their email address FLastA@domain.com to FLastB@domain.com.

I'm run a delta sync to AAD and I see that all the changes are properly updated except for the email addresses. After some time passes I check in AD again and see that the email address has returned to its original value of FLastA@domain.com.

I don't want to manually modify their email addresses through EAC because I want the Address Policy to apply to them.

I'm not an experienced Exchange admin (obviously!) but I've not had this problem before when I wasnot in a hybrid deployment.