In the Azure portal, for Azure Functions, I've found that the Monitor section for individual subfunctions is not infrequently a bit buggy, in that it misses out some function runs, particularly for functions trigged by a timer. To check whether the function actually ran on a particular day, check the logs for the function: they are usually far more complete.

If App Insights is not showing any data for a .NET 6 (or 5) web app, configure it within Visual Studio

This shows you how to add a simple Application Insights query to get your top requested pages which you can then add (pin) to an Azure dashboard.

If you look at a .NET 5.0 App Service (website) in the Azure portal, you will currently (3 Feb 2021) see that the Applications Insight link in the left hand menu is disabled, with a tooltip when you hover over it saying that Application Insights is not yet supported for ...