Tracking of telemetry appears to be lost if TRACK POST is performed while network is down.

Reproduction Steps:
With Network On
Perform a trackEvent
Wait for TRACK POST
Perform a trackEvent
Turn off Network
Wait for TRACK POST
Turn on network
Perform a trackEvent
Wait for TRACK POST

In Insights, only trackEvent 1 and 3 are captured.

Is it possible to use navigator.online to decide whether or not to perform TRACK POST?