(SOLVED) Cannot aad user

[wimduk]

I have a SparkyLinux computer and would like to add a new userto that machine. The current user is marja
To do so I have executed the following commands
1. sudo useradd jan (plus sudo password)
2. sudo passwd (plus 2x password for jan)

During login I filled out the form with user jan plus the password for jan.
The machine continues processing but after a few seconds I am prompted to fill out the form again (etc.)

Looking at /media i see marja and root, but no jan
If I reenter the command useradd jan the computer answers that user jan already exists

SOLVED
I removed user jan and added jan as new user with the adduser command and user jan was correctly added

What do I wrong and who can help me?
With many thanks in advance, wimduk