Users and groups (Unix server)

I noticed today on one of my user accounts, under the File Manger, the ownership under ‘users’ and ‘group’ appears to have changed.

Normally the user / group would look like this:

accountname : accountname

Now it’s displaying:

accountname : toontje0

I added a new domain to the account and ownership looks ‘normal’ on it:

olddomain1.com accountname : toontje0 olddomain2.com accountname : toontje0 newdomain.com accountname : accountname