Nextcloud user deleted bug

I want to delete the user on Nextcloud and all its contents but this article appears. I deleted the Nethserver user and group then deleted Nextcloud but when I created the same account again the contents that I uploaded were reappeared at Nextcloud?

How did you delete Nextcloud?

You may delete a user in nextcloud to remove all files:

Maybe you have to delete the user in nextcloud first before deleting in Nethserver…

I have followed the link but still it says “Cannot delete user” I have to delete the manual through the user and nethserver group then delete the user folder and then delete the database user