I am dealing with a quadcopter that has a thrust to weight ratio of approximately 1.3-1.6. When we fly in manual mode the behaviour we see is that the quad lifts off the ground initially but cannot really sustain itself in flight and starts to descend again.
In ideal condition, you drone should start hovering at 50-60% throttle, so you have room for other maneuvers.
If motor prop, can’t provide such thrust, nothing can be done with code. change the motor prop combination, change to 12S battery or check for other alternatives.