Hi Janne,
There are few different instances of Central running currently based off regions.
The login URL is dependent on the central instance to which you are registered.
When you register for Central, an email is sent out requesting to activate the account.
We need to use the login URL mentioned in that email.
In case you try to use a different URL which belongs to different central instance, we will get the following message:
"Your User ID is not registered with Aruba Cloud Platform".