The tentacle finds the octopus server via a reverse proxy so it is able to register with the server. Then the server is able to correctly use the proxy to communicate with the tentacles.
As I mentioned with teh web proxy configured I can use script console to trigger a webrequest from the tentacle, and that does use the webproxy. However the acquire package step running on the tentacle does not.
For the moment I've worked around this by creating another reverse proxy for our nuget server and putting in a custom hosts entry on the server.
I can only use the internal proget server we have so I don’t have different versions to try I’m afraid.
I’m not sure why the proxy configuration would behave differently depending on the version of the target endpoint.
It’s working fine with my reverse proxy setup so I’ll just leave it that way for now.