Can't install kubuntu 24.04 on 2nd attempt because useradd is throwing exit code 9 (group exists)

wanted to reinstall because user name and login name were not what i wanted the first time.

tried using gparted to completely remove the previous install, including a new partition table.

still this error keeps me from installing

i know this is not a kubuntu forum but how can this error exist on a completely fresh install on a completely empty disk?

how does it know about the previous attempt?