Esc calibration under 3.6.6

Good day,
im trying to calibrate esc under arducopter 3.6.6, I have the following motors t920kv with air gear 20a esc, after many trials the issue is still the same, I’ve also change the servo function without a positive result.
I’ve tested the x2.1 with same firmware with hobbywing 35a esc blheli/oneshot with dys 2400kv motors without any issue.
How i can solve it?