I've recently secured my multisite with a wildcard SSL certificate. I'm trying to avoid the warnings when trying to log in to a domain-mapped site, by redirecting all login attempts to the original subdomain URL (from visiting the login link in the admin bar, attempting to visit domainmappedURL.com/wp-login.php, and when using the Meta Widget). WordPress.com does this on all of its domain-mapped sites.
Would this be an .htaccess redirect rule? I see here they have redirected to the root domain: https://premium.wpmudev.org/forums/topic/redirect-all-wp-loginphp-files-to-root-file
I would rather stay on the subdomain site, but be redirected to the secured original subdomain.
Any help you can offer is appreciated.