Domain Mapping Admin URL

Hello guys!

This is my first post (so please be gentle :smiley:). I'm starting with my first Multisite installation and I already have some issues. This is the first one.

I'm using Domain Mapping plugin to give my customers the ability to use their own domain and it works fine. The problem is that the ADMIN URL is still based on my main domain so for example:

STANDARD CUSTOMER URL: company.expromo.pl
NEW CUSTOMER URL: company.com

STANDARD CUSTOMER ADMIN URL: company.expromo.pl/wp-admin
NEW CUSTOMER ADMIN URL: company.expromo.pl/wp-admin even if I go to company.com/wp-admin

This is very bad for me because some plugins (like Google Maps plugin) need the main URL to be the same to work (because of the Google API). Also it's very confusing for my customers and they feel like they don't have everything that they paid for.

Please help me with this.

I'm attaching a preview of what happens.