Login fails behind proxy

I’m using Particle Workbench behind a proxy (see my other solved issue). I was able to install the Workbench, but now I cannot login to Particle.

$ particle cloud login
? Please enter your email address myemail@gmail.com
? Please enter your password [hidden]
! There was an error logging you in! Let's try again.
! tunneling socket could not be established, cause=getaddrinfo ENOTFOUND 9400 9400:80 

My proxy address is set to http://xxx.yyy.zzz.qqq:9400. I made up the xyzq, but the port is 9400 so I imagine that is why it is displayed in the error message.

Thanks in advance for any help.

Let me drop a few issues from VS Code which may be related to assist anyone that may work on this issue: