Who redirects Umlaut domain names in browser to transliterated domain name?

I have a domain that contains an Umlaut like that:

https://spaß.de

"ß" may be transliterated to "ss".

Now when I copy and paste this text into Chrome or any other browser, I'm taken to

https://spass.de

However, the 2 domains have different owners, and the owner of "https://spaß.de" will never get any traffic to his site.

Is there any authority that redirects Umlaut domains to transliterated domains, or is the browser responsible for this? I have tried all kinds of browsers, they all show the same behaviour.

Thank you for any insights.