Dear @SaiKishor-MSFT ,
Thanks for picking this up so quickly. I could indeed solve the immediate issue myself: When I tried to create the connection monitor in Azure CLI, it responded with a meaningful error message telling me that the subscription was not registered for Microsoft.OperationalInsights. It was working fine (both in the UI and through CLI) when I added the registration.
Which leaves me with the following question: Why does the UI not give any meaningful error message? “Connection Monitor Back-to-front-HTTP-test creation failed” was the only error message I could see in the UI.
I also noticed that the failed transaction did create a Back-to-front-HTTP-test connection monitor. I could see that through the CLI, but not in the UI. So it seems the failed transaction was not cleanly rolled back.
And one more suggestion: You should add a hint in the exercise that the subscription must be registered for Microsoft.OperationalInsights. In a later exercise, "Troubleshoot a network by using Network Watcher metrics and logs", it is noticed that the subscription must be registered to microsoft.insights.
Thanks and best regards,