Non-GPS navigation with OAK-D

Hello Guys,

I was just exploring Non-GPS navigation with my Luxonis OAK-D auto focus camera along with RPi 4B+ on board. I followed each step as provided on (Luxonis OAK-D — Copter documentation). But whenever I try taking a flight in AltHOLD mode with the navigation scripts on, the drone starts rapidly losing altitude after reaching an altitude of just a few meters and falls to the ground. I even tried taking off in Alt Hold with the scripts off and running them once I obtained a stable flight, but again I got the same results, as the drone again fell to ground almost instanteously. I don’t know, where am I going wrong as I set all the parameters exactly as guided on the wiki page. I’ve also attache the log file of the flight for reference. Can anyone please help me out if tried following the guide and getting any successful results.
29_3_25.BIN (603.9 KB)