Account names with accents override the name without accents

The bug

Account names with accents override the same name but without accents. See the example below for more information. But, when looking up Sengångaren on the Mojang API, it returns a 400, Bad request. If you search Sengangaren without the accent, it links redirects to Sengångaren.

Example

Sengångaren exists but Sengangaren without the å (=accent) can't be claimed while it does not exist (see above for more information).