IDN Web Domain
In this example i use the Domain:
IDN: äüötest.de ACE-String: xn--test-koa2itb.de
if i add a new Website with the Domain: xn--test-koa2itb.de all looks fine the website is added and translated to äüötest.de in the list of websites, and is accessible from the Browser.
After modifying this website with no change, just go to edit and click save then the URL changes to [strange-chars]test.de and is not accessible from Browser any more.
[strange-chars] is because i can´t post them here, got an Database error :-)