Virtualmin creates new SSL certificate for each subserver

I have a server with a wildcard SSL certificate. The server has also some subservers, which use the same certificate. Today I wanted to create a new subserver but now Virtualmin is creating a new certificate for the subserver instead of using the one from the parent server.
What went wrong? What can I do, that Virtualmin uses the certificate from the parent server?

EDIT: I just solved the problem. I reinstalled the certificate from the parent server and after that I disabled and enabled the SSL website of each subserver