Apple Business Manager Azure app stopped syncing

Since a few days my Apple Business Manager Enterprise App in Azure was quarantined. I had no configuration changes, it just suddenly stopped. I have two groups which contain the users I want to sync. It seems it cannot use groups at all anymore. If I assign users directly it will work. But that's very inconvenient for us. Was there any change lately to explain why this does not work anymore?

Group User

Apple Business Manager Azure app stopped syncing
 
 
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