Repurposing an SMTP:Alias email from ASDI EDIT with hosted O365 via dirsync.

I had an existing SMTP email alias tied to a users account.

I manually removed it in ASDI Edit.

I waited overnight to make sure the domain controllers and dirsync synchronized.

I went into O365 to create the shared mailbox by the same email address name and says it still in use connect to the user I removed it from.

Error

The proxy address "SMTP:emailaddress@server.com" is already being used by the proxy address or LegacyExchangeDN of "original user". Please choose another proxy address.

How long does it take for it to be removed so that I can create the mailbox?

Or is there a way in PowerShell that I can expedite the process?

Haven't been able to find anything on the interweb for a solution. Thanks.