Before a hybrid setup was done we had a user already created in Azure AD/Office 365. We had all users created first in Office365 as email accounts which naturally created them as users in Azure AD. We then started creating a Windows AD Domain and we wanted to start syncing the users. We created, in the Windows AD, all users exactly how they were in Azure AD and all of them synced fine, except for one. For some reason Azure AD created a new user that had numbers appended to the end of the username and said that it was synced with Windows AD. The actual Windows AD user is still in Azure but it says it is not synced to Windows and since the wrong user is synced to Windows I can't delete it. Any ideas on this?