Register/ login problem

[TheCodery-eu]

Hello I am using a new clean installation in a subdirectory in a shared server. Changed the env.php file and all the links are working and the pages are loading properly. BUT I have a problem with registering as a user. I enter my details but after I click register the website just reloads and there aren't any new logs in the database. I have tried adding a new user through the admin panel and it is saved in the database but I still can't login it either stuck on authenticating or if I am trying to login directly in the main menu or the website just refreshes when trying to login in the login page. I have also noticed that when I logout of the admin account I get stuck as the default John Doe account and can't logout from it until I open the website in a new page. what's wrong?