We tried to build a Prandtlplane but don't know how to analyze the flight

Hey all,

We recently tested our drone which we have been making from scratch. We made it like an airplane so that we can test the aerodynamics of the drone. We put it in stabalize mode and tried it out. We’ve been trying to figure out what happened but can’t seem to figure it out. Does it have to do with Stabalized mode?
Please help!
Pixhawk log:
More info/ visuals: