Bug Unity behind Proxy does not use provided Proxy-Credentials

Hello everyone,

I know that I can set proxy settings through environment variables(HTTP_PROXY, HTTPS_PROXY) and unity will use them also when I attach the credentials for the proxy as a prefix to the proxy it does work, but unfortunatly not for all requests unity is making.

I can not fetch packages because of this issue. Unity tries to contact api.unity.com over the proxy but does not use in this case the provided credentials a error message is given back indicating error 407.
I observed this with wireshark. Unity-Engine does not inform itself about this issue.

Can someone help me please? Maybe I am doing something wrong?

 

My guess was right.
I have setup a local proxy without credentials wich delegates the requests to the main proxy with the credentials applied. Now Unity works like it should.

This said, the conclusion is that Unity is not able to handle proxy addresses with a basic authentication.