Hi,
Could you check any module related to social login in modules in back-office.
If you find module and disable it then social login will not be shown.
I had installed paid social login module for my websites.It helps to login with facebook,google and linkedin account.This module can be activated and deactivated using back-office modules.
In your image social login is blank box.
PrestaShop Tutorials Videos [How to do Tasks]
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