you could try to set your terminator to null String "". 
it is optional accordig to docs
https://docs.intersystems.com/iris20251/csp/docbook/DocBook.UI.Page.cls?KEY=GIOD_tcp#GIOD_tcp_open

• terminators

Optional — A list of up to eight user terminator characters that will terminate reads on the TCP binding device. If you specify both T mode and terminators at the same time, T mode is ignored.

I wonder how you expect to know that your input is complete without any terminator.
And according to your example, you also don't have a fixed length:
Withoit an clear signal timeout seems to be the only way to know you are complete.

You may read input character by character without guarantee  
how do decide for 1 or 10 or 100 or 1000  ?
Some ending character (eg. not numeric) or a fixed length is required

Confirmed. I just checked:

• containers.intersystems.com/intersystems/iris-community:2025.1
• containers.intersystems.com/intersystems/iris-community:latest-cd

license valid to 4/6/2026

My personal preference would be

• verify Websockets with a js client (even in CSP)
• then move it to IRIS with all hidden and default features if required at all.

You may check all the old WS examples in OEX

Hi 

your code
Set WebSoc=##class(%Net.WebSocket.Client).%New(WebSocURL,cre,evl)   
Just uses the Default %Net.HTTPrequest that contains url port, ....
But %New offers more
• Methode %OnNew(pURL As %String, pCredentials As %Net.WebSocket.ICredentials = $$$NULLOREF, pEventListener As %Net.WebSocket.IEventListener = $$$NULLOREF, pAcceptedProtocols As %String = "", pRequest As %Net.HttpRequest = $$$NULLOREF) als %Status
and in %Net.HTTPrequest you have a property port
https://docs.intersystems.com/iris20251/csp/documatic/%25CSP.Documatic.cls?LIBRARY=%25SYS&PRIVATE=1&CLASSNAME=%25Net.HttpRequest
I never needed it as protocol ws and wss was sufficient.
But there is no other place for a port to be assigned


 

You mentioned:

WebSockets are enabled on ports 80 & 443, but the code fails

Websockets work bi-directional
SO: Did you assign / map  those ports also in your docker-compose ?

Docker  build fails :

ERROR MESSAGE
! iris The requested image's platform (linux/arm64/v8) does not match the detected host platform (linux/amd64/v3) and no specific platform was requested 0.0s
✔ Container docker-setup-1

The required Platform is not mentioned as a Prerequisite

Is it also available for amd64 processors ?

Possible workaround:
 

$ListToString(%DLIST(DISTINCT(REPLACE(ARCIM_Desc,'<br/>',''))),'<br/>') as "ARCIM_Desc", 

Details on $LISTTOSTRING  
Your source seems to contain the <br/>
Try a different separator e.g. @ to verfiy it.
If it is in and you can see it, HTML tags < > might be escaped for some reason and not be
recognized but displayed as text instead
 

	#; Recompute hash here now we have the lock
	Set hashval=$$$hash($lb($$ClassIndexTS^%SYS.cspServer2(db),$roles)_rangelist)

$ROLES of the user might also be involved in the issue

As a first step, I would check file/directory owner + protection in WINDOWS related to Studio Windows user
< DIRECTORY> is not so specific on the reasons

again YES !
Any expansion is related to an extension of the internal mapping structure of the  .DAT  file
written to disk If you don't have any restrictions on disk space, you consume the related
overhead in 1 single shot at a time that you control (e.g., startup)
 

A possible escape from that trap could be to use a dedicated box
That just runs TCPTRACE
So the message runs CLIENT -> BOX -> SERVER -> BOX -> CLIENT

Of course, a qualified network manager might use Wireshark for this issue
 

HMMM.
Are you sure that WS and WSS Protocol are enabled on the Webserver
https://ac1.mqtt.sx3ac.com

And any firewall in between?