Hi @AdrianC
Welcome to our forum!
What is your account? Outlook.com or Microsoft 365 or something else?
And what is your previous workspace?
To better assist you to solve the problem, would you please provide a screenshot of the error? (In order to avoid privacy leakage, please remember to hide your personal information.)
As i know: It seems a known issue after the migration usually registry fix or escalation to Microsoft is the solution, check this thread and workaround. More information: Autodiscover issues After migrating from google. - Microsoft Q&A
In addition, i find a similar thread that many people find it useful, you may feel free to refer to it.
Hope it helps!
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