spatie-laravel-permission shows other than the given permission why ?

guys iam working with a project.

i have installed spatie/laravel-permission

everything worked fine

i followed this link : https://scotch.io/tutorials/user-authorization-in-laravel-54-with-spatie-laravel-permission

but whats the problem is

i have given like this in my nav bar

@can('Add Student')

                        <li><a href="{{ route('StudentAdmission.create') }}"> Add Student Admission</a></li>

     @endcan

its a school project, so for a staff i have give a role teacher and for teacher i have given the permission add student addmission.

but other than this everything is showing in the nav bar.

iam unable to find out, like this i did for other nav bars with other roles and permission the same issue.

for a specific role i have given few permissions but other than that permissions remaining are shown why?