Octocopter ALTHOLD mode crash [land detected in the air]


Hello! Need help to investigate and fix crash reasons.
I think I know reason but I need confirmation and advice how to fix: I use ESC with reverse (Hobbywing Xrotor pro 40A), and this ESC uses timings 1500us for stop, 900us for full throttle reversed and 1900us for full throttle normal.
So I set PWM_MAIN_MIN=1400 and PWM_MAIN_MAX=1900
And I have very low hovering throttle - about 20%, I think due to low hover throttle, I’ve got undesired land detection in the air.
Can you please confirm my thoughts and give me an advise how to fix this issue?