GetUserGrantByID for granted projects not working

Hello, i am trying to get the user roles from a user but its not working. I am using the GetUserGrantByID call. i give to the call the userid and the resourceId of the project but all i get is: {"Status(StatusCode="NotFound", Detail="User grant not found (QUERY-wIPkA)")"}

The user has roles in this project for sure. what am i doing wrong?