Double login required on two different forms

I have installed the Limit Login Reloaded plugin on WordPress 5.4.1, where we used the /admin URL to login. Now it redirect us to /#login, and we have to login again. If we try the /#login URL alone, it does not let us to login.

I removed the plugin, but the same behaviour continued. Even worse, this time we were locked out (fortunately, admin was still logged in). So I have to reinstall the plugin in order our users to be able to login again.

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