Delete User and his Folder TLJH

I have created 3 users and uploaded files to them to see what happens when i delete them. The Problem is that the folder at /home still exists after that so i deleted them manually. But when you create a new user with same username the spawner will get timeout everytime while starting the server.
Is there any fix to create users with same username now and is there any possibility to delete user completely (also there /home… folders)

After a little bit of testing:
Solution: after delete the user on jupyterhub use this command in terminal:
sudo userdel jupyter-placeholder (replace placeholder with the username)

But now the problem is that when you want to create a new user with FirstUse Authenticator that the Login still says invalid username or password but there is no user anymore with this name.
Have somebody a solution for this?