Can't reuse QuickSight account name. "The provided account name is not available"

Hi, I want to change the login method of QuickSight from the normal to Active Directory related. There's no option to switch in QuickSight, so I tried to recreate the QuickSight account. I deleted the account and tried to re-create the account with the same account name, it said "The provided account name is not available".

How long should I wait for reuse the account name in QuickSight? Or I misunderstand something about recreation?

Thanks,