Hi
We have an external portal with two ArcGIS servers. We have a web adaptor box in the DMZ and the servers are on our local network. We are using HTTPs only on the portal and the servers. Their is a valid externally signed certificate on the Web Adaptor box. We are running ArcGIS 10.5 Enterprise.
This set up was working well until last week when Infrastructure attempted to block our Admin URLs from the internet.
The changes weren't successful and a roll back was applied. However we are no longer able to connect to our portal servers through Arc Catalog.
When we try to use our existing Arc Catalog connections we get the following error

And when I try and create a new connection in Arc Catalog I get

https://mywebsite.com/server/admin

I have been running python scripts to validate that all the services on the servers are running and these scripts are now failing at the get token stage.
Calling getToken Function
HTTP Error 500: Internal Server Error
I had a look at fiddler and it looks like the arc catalog can get to our website using port 443 then it tries to redirect to the server using port 6080 instead of port 6443?
tunnel to mywebsite.com:443 0
tunnel to mywebsite.com:6080 512 no - cach, must revalidate
tunnel to mywebsite.com:6080 -1
I am still able to generate a token using the the Web URL.
I'm not a network expert so I'm trying to figure out if this is likely to be a firewall issue / network problem or an ArcGIS issue.
Any help would be appreicated.
Thanks,
Clinton