Can not Add Arcgis Server
Hi,
I have a weird condition and i need an explanation. 
I have 2 method of LAN Settings. First method is "Automatically detect settings" and the other one is "use a proxy server for your LAN".
I want to connect to a arcgis server service (hosted by other department in another company).
Using either LAN settings, I am able to access it via web browser (Chrome and IE. Dont know in Mozilla).
Then I want to access it via ArcMap by choosing GIS Servers -> "Add ArcGis Server" --> Use Gis Services. If I choose "use a proxy server for your LAN", i got an error "we were unable to connect to someonlinehost/agsadaptor/rest/services. Error: Service unavailable. (Status code 503)" . If I choose "Automatically detect settings" for the LAN Settings, I can access it.
Why is this happening ? Whats the difference between the 2 methods from ArcMap point of view ? Why both method works using web browsers ?
Iam very curious
[Arcgis Desktop 10.6.1 with recent TLS patch]
thanks
