Problem logging into the user panel

Welcome
I purchased a control panel license
I installed the board on my server
And I created a regular user for my site
But there is a problem in logging in. The user receives an error message in the information. I changed the password for the account more than once. I reinstalled the panel again and it is the same.

Are you able to login to the admin panel just fine (2031/2087)?
Only with end users logging into port 2083 do you experience this?
Does it show "logging in" and then kicks you back to the login page? Sometimes logging in 2x in succession will get you past this bug.

Are you able to login to the admin panel just fine (2031/2087)? yes
Only with end users logging into port 2083 do you experience this? yes
Does it show "logging in" and then kicks you back to the login page? Sometimes logging in 2x in succession will get you past this bug? No

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You can show the following file like this: /home/USER/.conf/cwp.ini

You can show the following file like this: /home/USER/.conf/cwp.ini

https://i.imgur.com/gsyg7VQ.png

* Note: The problem only occurs in the domain to which the server and DNS are connected
We tried creating an account for another site and accessing the control panel works normally.

The problem is only updating the domain account associated with the server (hostname and dns)

Is the server FQDN a subdomain of your main domain? I hope it's not just the main domain or the www subdomain/CNAME...
My VM servers are srv1, srv2, etc. Bare metal hosts are host1, host2, etc. All have valid DNS and rDNS entries.

Is the server FQDN a subdomain of your main domain? I hope it's not just the main domain or the www subdomain/CNAME...
My VM servers are srv1, srv2, etc. Bare metal hosts are host1, host2, etc. All have valid DNS and rDNS entries.

I have a vps server
I connected the server to this domain:
https://www.tec-host.com/
server.tec-host.com
ns1.tec-host.com
ns2.tec-host.com
I created a regular website account for him, and after creating it, I cannot enter the control panel
Create an account for another site. I was able to access the control panel.

Is it because the domain is linked to the server, so it is not possible to create an account for it because it is used in the server settings?

Yes, exactly. You may even want to purchase a domain just for server management, with no public-facing web sites. I would suggest tec-host.net in your case.