Hi @Sam Johnson • Thank you for sharing the feedback with us.
Based on the feedback, I have raised a UVOC item in the feedback portal and will notify the product group as well. I am sharing the link to the feedback so that others facing this issue can find the information and upvote it. Kindly upvote the feedback.
https://feedback.azure.com/d365community/idea/43d16ef9-6427-ed11-a81b-6045bd853198
This limitation is documented under the Important note in Associate or add an Azure subscription to your Azure Active Directory tenant document:
When you associate a subscription with a different directory, users that have roles assigned using Azure role-based access control lose their access. Classic subscription administrators, including Service Administrator and Co-Administrators, also lose access.
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