Trouble with alias domains

I am running a Virtualmin server which is currently hosting 10 websites. The domains are registered elsewhere, and I an pointing to the Virtualmin server with A records at the nameservers located elsewhere.

I have the “standard website” standardwebsite.com showing up normally.

And then I have myenglishwebsite(com) which I have registered on the server. I have then two other domains, myswedishwebsite(com) and mydutchwebsite(com) registered as aliases of myenglishwebsite(com).

The problem is, whenever someone try to visit myswedishwebsite(com) and mydutchwebsite(com) they do not come to myenglishwebsite(com), but instead they come to the standardwebsite(com).

I am not sure why. I do understand that standardwebsite(com) is the “main domain” for the website, and that is the default website… but since I have created the mentioned domains as aliases of myenglishwebsite(com), I don’t understand why it shows the standardwebsite(com) content and not the content of the website for which the alias has been created.

Ps: The domain names are just examples, not the real names.

I hope someone can help.

Best regards,
Sigbjorn