Hide WordPress Login Page issues

I was getting lots of brute force attack notifications…
We’ve just locked out the host 94.158.244.117 from https://mysite.com/ due to more than 5 failed login attempts.
So I followed the instructions here: https://premium.wpmudev.org/blog/hide-wordpress-login-page/
I used Defender to Mask Login Area.
I have now substituted two new issues for my original.
First, now I’m getting autodiscover 404 errors:
We’ve just locked out the host 96.65.27.193 from https://mysite.com/ due to more than 20 404 requests for the file /autodiscover/autodiscover.xml.
How do I fix this please?
Second, this is a multisite installation. Now, when I’m on the multisite dashboard and click a subsite dashboard link from the My Sites dropdown, it resolves to the subsite’s wp-admin page and I get the This feature is disabled error page.
To access the subsite’s dashboard I have to manually visit subsite.com/hiddenlogin (for example.)
Do you have any advice for this please?
Thanks,
~Bob