Hi Jöran Malek,
Thanks for reaching out to Microsoft!
The error message "The provided drive id appears to be malformed or does not represent a valid drive." indicated that either driveID or itemId you are using is not correct. Ensure that driveId and itemId you are using are correct and properly formatted.
If you still facing the same issue, I recommend you raise a support case with Microsoft Graph, a Support Engineer will be able to look into this issue and assist you better. You can raise support ticket from New support request - Microsoft Entra admin center or https://admin.microsoft.com/#/support/requests.
Hope this helps.
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