Hi Roos =,
Thank you for reaching out to Microsoft Community. We are sorry to hear about the issue you are having on your Surface Pro 7.
May we ask if the device was linked to a work or school account?
Please go to Settings > Accounts > Access work or school
Please check if there is work or school account listed on this page. If yes, the issue is caused with this since the device is being linked to that account. Please try to remove/disconnect the account first then set up Windows Hello again. After setting up Windows Hello, you can then add the account again.
To disconnect the account: you may click on the account and Disconnect option will appear.
If this answer your question, we highly encourage you to inform our Community by clicking on Yes or marking my post as an answer. This will help other members who may have the same issue as you. Otherwise, don't hesitate to update us so we can further assist you.
Kind Regards,
Marrion Y.