wp-admin.php not redirected

I have some 404/undefined spam on my blog so I installed this plugin. I have also created a custom login page because of the brute force hackbots, so my wp-login.php isn’t working anymore. When I click wp-login.php it gives me an error 404. /undefined calls are redirected to my main page, but wp-login.php isn’t doing that. It’s now getting to my top visited page. Any workarounds?

https://www.ads-software.com/plugins/all-404-redirect-to-homepage/