@PuDerBaer Thanks for posting in our Q&A.
For this issue, in general, you can first remove the device group and then add the user group.
But it is not sure that every device configuration profile will no longer apply to the device group. In our official article, for windows devices, when remove devices from a group that's assigned the profile, some CSPs remove the setting, and some CSPs keep the setting, also called tattooing. So, it is suggested to try to test specific settings to confirm if it is available.
https://learn.microsoft.com/en-us/mem/intune/configuration/device-profile-troubleshoot#what-happens-when-a-profile-is-deleted-or-no-longer-applicable
If there is anything unclear, feel free to let us know..
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