How to disable automatically adding users when trying to logon

[#1]

We run a Qlik Sense server (v2.1.1) on a machine in our domain, and on a machine in a workgroup connected to the internet.

I've configured the authentications of these machines to the 'Windows authentication pattern': form (instead of the default Windows).

The problem is, whenever anybody is trying to logon on the HUB, even when the user does not exists, the typed in user is added to the users in Qlik Sense. Because one of the servers is available to the internet, we really want to disable this feature. If the user is not allowed, I do not want that user in Qlik Sense as a user...

How to disable this automatically adding of users?

[Gysbert_Wassenaar]

I see. As I understood it the mere attempt to log on would add the user, regardless of the fact if the user could be authenticated by an authenticated service. Guess I was wrong.

[garystrader]

Can anyone else reproduce this?  I can't.  I have forms authentication enabled, and I tried various random account names, including a fake account on the correct domain, and I couldn't get it to add users to the Users list.