Page is not loading for users registered

Hi, I am using codeigniter to create an online platform for a school. Admin logs in but when I try to create new users, they cannot log in. The link that is loaded is correct but the dashboard is not showing. The session works but still is not showing the dashboard. I wrote the same code as I wrote for admin but only admin can log in. What might be the reason for that?

Many thanks.

codeigniter version 3.1.11
php version 7.2.30