"Kinde treats usernames as case-insensitive. In other words, we ignore case. We do this because it eliminates the possibility of auth issues and fraud when two usernames are identical in every aspect except the case of one of their letters.
We are happy to support users choosing an aesthetically pleasing username combination, like RosyRose or BuilderBob. We just don’t also support separate identities for rosYrosE and BUilderbob."