Error 403 Forbidden and wp-admin/install.php

This is the error that appears and I get it daily but it dissapears after a while on its own but it comes back and sometimes does damage at the widget area or something, it started to show up often since yesterday

Here is a screenshot

Screenshot

I have a few plugins like Wordfence , Wp Security and have changed the table prefix with the plugin and the wp-admin to something else for logging in.

Maybe that is some clue ?

Thank you!