I've got an Azure IoT Hub (Public Access Restricted) and having a Time Series Insight. And I want to connect this time series insight to IoT Hub over the private connection so I don't need to make IoT Hub publicly accessible.
Creating a private endpoint in Time series insight didn't work for me.
I've got the answer, So the issue was while keeping your IoT Hub Private or on the Selected IP Ranges, There is a checkbox in the end that says Do you also want the IP Restriction applied on Build-in Endpoints. Uncheck it and problem solved.
So in the end, To maintain the connectivity to the TSI environment with IoT Hub on the private endpoint, The IoT Hub can remain on the private network but built-in endpoints should be public.
That's my understanding.