@Frederik Adsersen, Thanks for posting in Q&A. Based on my researching, I find a known issue in Hybrid environment. After the user provisions a Windows Hello for Business credential in a hybrid key trust environment, the key must sync from Microsoft Entra ID to Active Directory during a Microsoft Entra Connect Sync cycle. Before it is synced, it will get this error.
Hope the above information can help.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.