Looking at the BlackBox. Can anyone tell me what the field stateFlags is for? Trying to diagnose strange behavior with momentarily losing control of quad and notice this on the graph and can't figure out what it is used for.

The stateFlags show if certain conditions are active or inactive, like failsafe, small angle, armed, etc.

What, specifically, do you want to understand?

You can always post the log and a description of what the problem is.