Betafpv 75 Pro2 Throttle Problem

Hello, I had just finished building my first betafpv 75 pro2. I had set up everything correctly, but when I arm the quad and throttle up a bit it will move up a bit and suddenly start moving up a lot. Does anyone know why this is happening and how to solve the problem?

Air mode can cause this to happen freaks me out to bro. As long as it acts correct in the air your good.