Role Assignment Restoration: If your RBAC role assignments were lost during re-authentication, you may need to reassign the necessary roles. Ensure that your account has the appropriate permissions to manage role assignments.

If Azure RBAC role assignments were lost, they must be re-created. A Microsoft Entra Global Administrator can temporarily elevate access by turning on Access management for Azure resources, which grants User Access Administrator at the root scope. After signing out and back in, that access can be used to assign the required RBAC roles, such as Owner, on the affected subscription or scope.

To reassign roles:

1. Sign in as a user that has Microsoft.Authorization/roleAssignments/write, such as Role Based Access Control Administrator, at the target scope.
2. If the account is a Global Administrator but has no subscription access, go to Microsoft Entra ID > Properties and set Access management for Azure resources to Yes.
3. Sign out and sign back in so the new access is detected.
4. Go to the subscription or resource scope and re-create the missing role assignments.
5. If changes were made recently and are not detected, allow up to 10 minutes for Azure RBAC changes to take effect.

Important cases from the documented behavior:

• If a subscription was transferred to a different Microsoft Entra directory, all role assignments are permanently deleted from the source directory and must be re-created in the target directory.
• If a resource was moved, direct role assignments on that resource are not moved and must be re-created.
• If using PIM and the account is eligible for Owner or User Access Administrator, that role can be activated temporarily to remove or restore access as needed.

References:

• Troubleshoot Azure RBAC
• Steps to assign an Azure role
• I missed the deadline of transition to RBAC in Azure by 31 August 2024, access to all resources is lost. - Microsoft Q&A
• I am the Global Admin of my account and I accidentally deleted my owner permission - Microsoft Q&A