Hidden cloud- User?

I have an user in the List of cloud-Access, but not in the List of the NAS in the Dashboard.
When i would create the User the username is to long.
I wanted to create the user official and delete him, that the cloud-User is also deleted. like the workaround of hidden shares.

How can I delete a to long username for cloud???

@MathiK My Cloud NAS user names are limited to 16 characters. I’m trying to understand how you may have entered in a situation where the NAS user is deleted but the Cloud User is not deleted??

The System Only Restore would resolve your issue as all users are removed.

Yes the user is longer than 16 chars.
The user is called „christoph_pelzeder“
If I create a (wd)user then the input stops at position 16, like you mentioned.
Perhaps, the user was created because of a share in os3 in the mobile app?

I also have similar problem but my user names are less than 16 char. How to remove them?