Struggle analytics uses the loadEventStart to measure struggle associated with page load time.
Previously, Struggle analytics used renderTime to measure page load struggles. This was problematic as renderTime ignored page load struggles that were related to server or network delays.
To capture performance data for the loadEventStart, you must set the loadEventStart to false.
If no loadEventStart data is captured, Struggle analytics uses renderTime.
For information about loadEventStart see the section on Performance in the UI Capture reference.