Bug with loading admin-ajax

Hi.
After updating to latest version of domain mapping I noticed a huge issue and had to revert to a previous version (4.4.2.4).
From what i remember :
- on a subsite with a different domain mapped to it : when trying to add a category (or custom taxonomy) in admin, or when trying to "quick edit" an article, nothing was happening.
- i opened the console and realized there was an error loading the admin-ajax file
- the path to the file was http://subsite.com/wp-admin/subsite.com/wp-admin/admin-ajax.php instead of just http://subsite.com/wp-admin/admin-ajax.php

This might be a mistake on my behalf, but I don't think so since reverting to previous version fixed the issue