Hello @Shane ,
Welcome to the MS Q&A forum.
This is the expected behavior. Global admins can't Revoke MFA sessions and Require Re-register MFA for their own account. I suspect this was done to prevent the self-locking GA accounts. Especially in a case if no one privileged left to unblock.
You could ask another global admin or user with the "Privileged Auth Admin" role in the tenant to Revoke MFA on your account or create another account with the specified roles and revoke yourself.
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Hope above answers your question and concern. Let me know if you need additional assistance. If the answer was helpful, please accept it and complete the quality survey so that others can find a solution.
Sincerely,
Olga