BetaFPV Cetus X with a Runcam Thumb Pro + Crash

Trying out the BetaFPV Cetus X whoop with a custom printed canopy with a Runcam Thumb Pro on top.
At first everything seems to go pretty well, but after a forward flip the drone becomes completely unstable and crashes.
anyone ideas why this happened? I guess the aerodynamics of this frankenwhoop is just catastrophic.