Unable to allow users to see role assignments on all their projects

I'm trying to allow users to see what roles they have on all of their projects.

It would seem that this should do this in policy

"identity:list_role_assignments": "rule:admin_or_monitoring or project_id:%(scope.project.id)s or user_id:%(scope.user.id)s"

However this doesn't work.

With project_id:%(scope.project.id)s it allows a user to list the roles of the project they are authed to but it doesn't work with user_id:%(scope.user.id)s"

I notice that when using the keystone client it treats filtering by user_id and project_id differently

When filtering by project it does:
/v3/role_assignments?scope.project.id=094ae1e2c08f4eddb444a9d9db71ab40

But when filtering by user it does:
/v3/role_assignments?user.id=d1fa8867e42444cf8724e65fef1da549

Is there something I'm missing here or is this possibly a bug?