The letter å is ignored when used in usernames. The letter is common in Scandinavian languages, mostly in Swedish, but is used in Norwegian, Finnish and Danish as well.
When added to a username in the Zwift settings, it is omitted when shown in-game. Using the letter a is unfortunately a poor substitute.
The other common letters in Scandinavian languages, ö and ä, are shown correctly. Probably because they are also used in larger languages such as German and Turkish. It would be nice to be able to show my name properly in Zwift and I am sure many other users in Scandinavia feel the same.