Hi,
I have the same issue. I could access https://copilot.microsoft.com/ but the side bar and Copilot Preview does not work. I get a message "We're sorry but we're unable to connect to the service at this time. Please try again later or refresh." If I disable Cisco Umbrella, it works but what exactly do I need to allow in Cisco Umbrella to make it work? We already have *.github.com, copilot-proxy.githubusercontent.com in “Selective Decryption list.” What else does Copilot need so it will be allowed?