Pre and Post Domain Modification Scripts doesnt work for Sub server


I have created a custom script which run before and after domain modifications like this tutorial:

System > Virtualmin Configuration > Actions upon server and user creation >  Command to run after making changes to a server

But it doesn't work for sub server modifications. I also tried "Command to run after making changes to an alias" but it still doesn't work for Sub Servers. I don't really want to create sub-servers as top level servers as I have few of top level servers but hundreds of sub servers.

It is a bug or am I supposed to look into any other settings?