I'm getting an ~ambiguous error message when I created a rule in Microsoft Entra, so an MS 365 group can get its members dynamically!

I created a Microsoft Teams private group, which automatically created a Microsoft 365 group. I set the group "Membership type" to "Dynamic User" and added the query: (user.directReports -ne null)

so members of the group can be only employees that manage other employees.

Every time I do it, the group keeps reverting back to Membership type: "Assigned".

Please help!

Thank you.