Display mean for timing matrices shows incorrectly on grafana

I am pushing timing matrices’ to grafana and displaying mean on grafana. i have triggered only one request.
but if i select duration with less interval for (eg. last 15 mins) then data shows correctly(i can see time on charts)

But if i select 24 hours duration with only one request received then selecting mean shows flat line with zero time.
So if i received only request and pushing time for one request then mean should be same for all intervals (either i select 15 mins OR 24 hours).

Could you please explain me how mean/median is calculated ?

Attaching snapshots.

welcome to the :grafana: forum, @rajagarwal790

what datasource are you using?