I'm getting the following error when trying to create an account in WHMCS:
Module Command Error
1007 - Client with login name 'jino' already exists.
I know an account with the same username exists on the server, but why WHMCS does not change the new account username automatically?

I tried other usernames to create the account, but got the same error

this is a windows server with plesk control panel

anybody can help?