Hi @William L ,
Welcome to our forum!
Once I reconfigure Outlook, I found tenant bounded to Old-A, even I used New-B ID to logon.
How did you reconfigure Outlook?
And does this issue occur with other users in your organization?
It's suggested that you could create a new Outlook profile (Control Panel>Mail>Show Profiles>add) and add the account to check if there are some differences.
Hope to help you!
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