I got the BetaFPV Advanced Kit 2, it flys well until today. I lost throttle control in the air, the pitch, roll, and yaw still works fine. The tiny drone keeps ascending so that I have to disarm and rearm it in the air to get control. After that, I checked the drone, I cannot see any wire/soldering broken or lose at all. I tried to fly several times, this issue happens intermittently. Any idea what might be the issue and how could I fix it？

These issue can be very difficult to troubleshoot without Blackbox log. Unfortunately there is no Blackbox on tbe Betafvp fc.