I noticed that the flight time value in the widget is not reliable (to me).
In QGC 3.5.3 for Android the flight time is lost if we disconnect / reconnect the telemetry link.
It seems that the value is extrapolated from the last TAKEOFF or ARM event seen by QGC, not from the Ardupilot.
I’ve seen that there is a mavlink packet where we can request the takeoff timestamp from the autopilot but it is not recommended for use in stable releases :
Is there another way to have more reliable flight time ?