We have a multisite with three sites - caregivermentors.com, careexperts.co and activityexperts.com
Caregivermentors.com is registered at GoDaddy and hosted at MDD.
For the other two domains, careexperts.co and activityexperts.com, we did the following:
Domains are registered at GoDaddy. Added A record at GoDaddy to point to dedicated IP at MDD Hosting.
On MDD Hosting, we added these two domains as PARKED domains.
On MDD Hosting, we then add A records for each domain that point to the IP at MDD as follows:
For careexperts.co, added *.careexperts.co A record
For activityexperts.com, added *.activityexperts.com A record
The problem is that when someone signs up to login to activityexperts.co - they are redirected to caregivermentors.com
we want each site to have their very own sign up etc