Issue in Postfix /etc/postfix/ file. mydestination didn't update the with my updated domain

Installed the free version of Virtualmin GPL on a clean install of Ubuntu 20.04. Didn't change my Contabo VPS servers default hostname before the install. So changed the hostname after the install with Webmin. While configuring Postfix I noticed /etc/postfix/ in the mydestination parameter didn't update all the way with my new domain.. It had a value that was the default from my VPS Contabo. It didn't' change to with Webmin hostname update. Don't know if it broke anything but just changed it manually.

Virtualmin version: 
Webmin version: 


Where in Webmin did you change the hostname?

Also, did the mydestination line contain the entire old hostname, or just a prefix of it?