Semester course -> grades for students group -> search return student that is not in the group

[EwelinaSkrzypacz]

Steps to reproduce:

1. Login to the application
2. Go to "Kursy w semestrze"
3. Add a course
4. Add a group with no students
5. Click "Oceny" on the students' group
6. In search write "lo"
7. See that some students are shown, but in the group there are no students

I'm trying to find why is that - if I find something I will add a comment

[EwelinaSkrzypacz]

When results are not paginated (for tests I deleted code paginate()->withQueryString()) search works