[BUG] Editing an account gives an error

Created a new account and then went to edit it. After clicking Save it does the job, but also produces this error:

Save Failed: Flex saveFile(demo): Cannot rename object 'Demo': key 'demo' is already taken account:///Demo account:///demo

Username: demo
Full name: Demo

Grav v1.7.0-rc.20
Admin v1.10.0-rc.20

I don't get this error on production though :/ Most likely some misconfiguration, just don't know what