"Connection refused" error when running Appian Health Check

Appian Health Check Application.
I am receiving a "connection refused" error when running the AHC application on the Request Analysis node of the Data Analysis sub process:

"Title: Error calling HTTP File Upload, Message: org.apache.http.conn.HttpHostConnectException: Connect to forum.appian.com:443 [forum.appian.com/54.229.82.89] failed: Connection refused, Details: "

I've deployed the latest plugin (v4.6) installed the AHC Application in the Dev environment.
I've checked the 2 constants (production and cloud).
The credentials (ahc.analysis and ahc.collection) have been setup and I'm using my forum username and password.

What am I missing?

Thanks

OriginalPostID-184598

OriginalPostID-184598