If new server template is created, either based on default template or empty, DNS settings always return to "From default settings". Steps to reproduce:
1) Create a new server template
2) Go to "BIND DNS domain" section
3) Select "Records below .."
4) Change some settings (eg. Custom TTL or disable m.domain)
5) Click Save and Next
6) Press Prev to go back
"From default settings" radio button will be selected instead of "Records below .." and all the setting will be ignored when creating a server.
This is a bug - you can work around it by entering something in the records box, like a dummy DNS record.
Thanks for a fast reply like always :).
Putting a comment like "; Dummy comment" in the records box does the trick without the need to put a proper DNS record.