@JMN-2253, Thanks for posting in Q&A. Based on my researching, "Configuration Manager MDM Authority" under MDM Authority once known as Hybrid MDM has been depreciated as of Sept 1, 2019. And we can't switch the MDM authority from Intune to Configuration Manager MDM Authority.
https://video2.skills-academy.com/en-us/mem/configmgr/mdm/understand/what-happened-to-hybrid
If you want to concurrently manage Windows 10 or later devices by using both Configuration Manager and Microsoft Intune, you can use co-management. Here is a link with more details for your reference:
https://video2.skills-academy.com/en-us/mem/configmgr/comanage/overview
Hope the above information can help.
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