IoT Dashbaord via Streaming dataset Line chart does not values.

I am using stream analytics dataset for live telemetry dashboard for iot sensors. Card and clustered column chart seems to work fine.  I have timestamp on X-Axis and temperature value on Y-Axis. So when I select 'Line Chart', It does not show graph at all and sometimes It does show graph but just a mere line instead of smooth graph connecting to each timestamp and temperature data points.  I am also using this dashboard in PowerApps as tile. Kindly suggest how to make this line chart graph show consistant line changing such as in this image below:

Ideal chart

Below are the actual charts snapshot.