Product:
Planning Analytics 2.1 Architect
Microsoft Windows 2022 server
Cognos Analytics 12.0.3
Issue:
After change in Cognos Configuration, you can not login from TM1 Architect, but you can login with TM1WEB.
Error you get: tm1camclient

Solution:
Inside Cognos Configuration for CA12, change the Edit Global Configuration under Action menu.
Remove the dot in front of the server domain name. So it says servername.domain.com instead of .servername.domain.com

The clue, it can be .domain.com, then it should work best if you only have one CA server to work with. If you have the servername in global settings then you should not use the period first.
Also ensure that the GATEWAY URL is the same in both Cognos Configuration and TM1S.CFG file

In the TM1S.CFG file it should be like this
ServerCAMURI=http://servername.domain.com:9300/p2pd/servlet/dispatch
ClientCAMURI=http://servername.domain.com:80/ibmcognos/bi/v1/disp
Then in TM1 architect under FILE – OPTIONS you enter the servernname to TM1 e.g. servername.domain.com and update.

Also change the value for “Allow session information to be shared between client applications” – change it to False can help solve the issue.
Save and restart CA12 service for the changes to take affect.
More Information:
Users are not able to log into Cognos Connection after setting a Domain property in the Global Configuration Cookie Settings. Submitting a login results in the user being redirected back to the login page without an error.
Diagnosing The Problem
Users unable to log in, are looped back to login page without error.
Resolving The Problem
Use the same server name qualification as that specified in the Domain property of the Global Configuration Cookie Settings.
Example:
Domain property: .travelinfo.co.nz
Prior to configuring this property, users accessed Cognos Connection using the servername ( http://servername/ibmcognos ). This URL no longer works with the Domain property set.
You will need to use the fully qualified server name in the URL to access Cognos Connection.
http://servername.travelinfo.co.nz/ibmcognos
An error message ‘Error with CAM Passport’ is seen when attempting to login into a TM1 server with Architect and Perspectives. The TM1 server uses CAM security (IntegratedSecurityMode 4 or 5 in the tm1s.cfg file). No error is seen during CAM authentication in TM1Web.
Cause
Incorrect Cookie Domain setting in Cognos Configuration for the Cognos BI Server used for CAM authentication.
Resolving The Problem
On each Content Manager server in your environment, remove or correct the Cookie Domain setting from Cognos Configuration. This setting can be access in Cognos Configuration from the Actions -> Edit Global Configuration… menu option.
Question
Cause
Launch “IBM Cognos Configuration -> Action -> Edit Global Configuration -> General” and configure the Cookie settings “Domain” and “Path” for each installation
Example:
Domain : .server1.domain
Path : /ibmcognos/
Domain : .server2.domain
Path : /ibmcognos/
Note: Do not forget the point before the server name.
Not sure of what is the correct setting in EDIT GLOBAL CONFIGURATION, you need to test what will work in your windows environment. Test to login to both your Cognos Analytics servers from same web browser, and from TM1 architect pointing to different TM1 servers.