@Alexander Horner In fact when we set policies as not configured, it means the remaining setting value will not be changed. Also some settings will still kept when the profile or policy is removed. Here is a link describes this for the reference:
https://learn.microsoft.com/en-us/mem/intune/configuration/device-profile-troubleshoot#what-happens-when-a-profile-is-deleted-or-no-longer-applicable
For our situation, we can check if the "Deny_Write" is in the registry key. If yes, remove it to enable Write Access to Removable Disks. here is a link with more details for the reference:
https://www.tenforums.com/tutorials/150715-how-enable-disable-write-access-removable-disks-windows.html
Note: Non-Microsoft link, just for the reference.
Hope it can help.
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