The problem is that your theme use plain text (wp-login.php) rather than standard WP login function (wp_login_url())

To fix this you should contact with theme author or edit template files yourself

If you’re not familiar with PHP :
1) Take a back up from your theme
2) Choose a login key/value and enter in HMWP settings (like hide_my_wp=1234)
3) Search within your theme files and replace all
wp-login.php
with
wp-login.php?hide_my_wp=1234
where hide_my_wp=1234 is your chosen key

Notes:
If wp-login.php has something else like redirect it should be
wp-login.php?hide_my_wp=1234&redirect=somthing

In other words, first sign should be always ‘?’ but separator are ‘&’

PS:
Consider these files /registration_panel/custom_function.php’ /registration_panel/login.php’ ‘/registration_panel/registration.php’