As InterSystems Technology is not an open source, it is not fair, in my opinion to compare the community open-source library of tools and examples to others (e.g. Linux, Apache etc.) since its not possible to use them without a valid license of a product (IRIS, Cache). As such its InterSystems motivation and also a rational should be to support this library, similar to their (massive) support for the community.

Norman,
If terminal is ok for you, but studio isn't, maybe you should try the VSCODE Lite terminal.

I'm using: IRIS for Windows (x86-64) 2024.1.4 (Build 516_1U) Sat May 31 2025 13:15:40 EDT
I get the same in Terminal (Telnet) and also in VS-Code Lite terminal:
MSCEME>write $ascii("♥") 
9829
 

HTTP 401 means "Unauthorized" check that the web application /terminal has the correct credentials and correct authentication methods (password, LDAP etc.)
(the /terminalsocket should be always unauthenticated, its the default)
to help you resolve this, you may use auditing, to see if there is a "login failure" when you try to access.