Jason Lemahieu (MadtownLems) on "[Plugin: WordPress MU Domain Mapping] Links from Frontend to Backend always end at dashboard"

Using 0.5.4.3, and recently upgraded several networks to WordPress 4.0 (from 3.8.x), and we are now experiencing the following issue on ONLY those sites which are domain mapped.

Consider the site at mydomain.com/foo mapped as mysite.com

When clicking a link from the frontend that should take you to a specific page in the backend (such as Edit Page or Edit Post in the top bar, or the link to go to the Comments screen), you end up at the dashboard instead of at the specific post edit screen. You first make a quick stop at the following URL (I've un-escaped it for readability):

https://mysite.com/wp-login.php?redirect_to=https://mysite.com/wp-admin/post.php?post=26&action=edit&reauth=1

Our Domain Mapping settings are as follows:
Remote Login - ON
Permanent Redirect - ON
User Domain Page - OFF
Redirect admin pages.. - ON
Disable primary domain check - OFF

Any ideas on what might be causing this, or something we could do to dig deeper and provide more info?

Thanks as always!

https://wordpress.org/plugins/wordpress-mu-domain-mapping/