Kristian Verlinna, Were you ever able to resolve this issue you had a few years ago? I am currently having a similar issue with Citrix VPN and ArcGIS Collector. I can access the portal and sign in and view maps but upon loading a map layers fail to load and result with an error message stating Layer Not Loaded Unable to load layer "World Imagery" from services.arcgisonline.com The request timed out. I have tested opening maps that do not contain any services from my portal and only a basemap from ESRI with the same error regardless of the map.
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