Recently I moved a WordPress Multisite to a single installation with the Duplicator Pro plugin. Everything worked great and the site has been running as a single site for more than a month without problems.
When going to "example.com/wp-admin" I get redirected to "example.com/wp/?redirect_to=https%3A%2F%2Fexample.com%2Fwp-admin%2F&reauth=1/wp-admin/setup-config.php" and it gives an error stating there is no wp-config file found.
Now when I try to log in on "example.com/wp-login.php" I get redirected to "example.com/wp/wp-login.php?redirect_to=https%3A%2F%2Fexample.com%2Fwp-admin%2F&reauth=1" and it prompts the WordPress install. It seems like it adds '/wp/' to the url which could be from the Multisite installation. I can also see a folder in the WordPress installation named 'wp', when changing this to 'wp_OLD' for example it justs redirects to a 404 page after logging in.
I have to add that the frontend of the site still works perfectly fine, it's just the logging in that's not working.
This problem just appeared randomly as there have been no changes to the website in the last couple weeks. Trying it in different browsers and with cleared cookies didn't help.
How can I stop the admin login from wanting to redirect to the /wp/ folder?