Hi @Larry Scola ,
Welcome to our forum!
Please kindly understand the Outlook tag here we mainly focus on general issues about Outlook desktop client. Based on my research, i found that it's useful to assign custom attributes by updating the user (PATCH /users/id). More information: Manage custom security attribute assignments.
Hope to help you! If the above doesn't help, i'm afraid that you need to post your case with Graph tag for more professional suggestions. Thanks for your understanding and support!
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