All users on the site have 'user' permissions (even if they also have 'student' or 'teacher' permissions as well at the course level), users who are not logged in have 'guest' permissions.
So, that means that mod/label:view is given to every possible user already (unless you have deliberately adjusted the permissions somewhere to add 'prevent' or 'prohibit' to that capability in the role definition).
This suggests to me that the problem you are seeing is something different to what you have described.
Can you explain exactly what is going wrong?