This is the config how to block MAM config on Android Phones.
Go to https://endpoint.microsoft.com/
Endpoint security > Conditional Access
Create new Policy
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Give it a name like No MAM – Android
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Select Users or group or all.
Select Cloud apps Office 365.
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Conditions -> Device platforms = Android
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Filter for devices -> Rule syntax
device.operatingSystem -eq “AndroidForWork” -or device.operatingSystem -eq “AndroidEnterprise”
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Grant = Block Access
Enable Policy.