Dear Rob PVICT,
Greetings! Thank you for posting in Microsoft Community.
I'm sorry you have issue with SSO with Office 365 apps. For the situation you encountered, we do understand the inconvenience caused and apologize for it.
Recently, there is a known issue for signing into Microsoft 365 Desktop Applications:
When users attempt to sign into Microsoft 365 desktop applications, they receive an error message.
Error: Something went wrong. [1001]
Please refer to this support article for detailed information: Error “Something Went Wrong [1001]” signing in to Microsoft 365 Desktop Applications - Microsoft Support
The Microsoft 365 teams are investigating this issue by analyzing logs provided by some affected users. If you see this issue, please ask your tenant admin to open a support ticket in the M365 Admin Portal: Get support - Microsoft 365 admin | Microsoft Learn
In order to expedite the investigation please include MSOAID logs in the ticket, Microsoft Office Authentication/Identity Diagnostic (MSOAID).
Appreciate your patience and understanding and thank you for your time and cooperation!
Sincerely,
Tina | Microsoft Community Moderator