Unable to de-capitalize my IGN when changing it

Hi,

I am unable to change my IGN from 'Wade' to 'wade'. I've been able to do so in the past without any issues; however, now it's saying that the username is already taken. I will attach a photo of proof that my IGN is 'Wade' and that I'm trying to change it to 'wade' and it's saying that it's already taken.