The problem persists. I noticed that even when I connect the copter to blheli suite and then I disconnect it, I am not able to fly because I have many warnings from AC such as bad AHRS, gyros still setting, etc. Initially I disconnected the batteries in order to reboot the pixhawk, but this does not work. Mostly one but sometimes 2 motors do not spin. When I perform the motor test in blheli suite all motors always run perfectly. I am running dshot150 on brand new tekko32 escs and I am using a pixhawk 1 with AC 3.6.8 installed. On my copter I have long range mavlink telemetry, frsky passthrough telemetry, FPV equipment with OSD and a cooling fan. IMU load durning flight is 50%, maybe the motor start problem is due to the fact that the board is overloaded?
I also noticed that I have to use an old version of blheli suite in order to connect my escs and read the blheli settings but I do not know if this is related directly to the motor start problem.
My last option is just to reboot the pixhawk from mission planner (after connecting all escs to blheli suite) without having to unplug the batteries. Keeping current to the escs while rebooting AC might solve the issue temporarily.
This is annoying because dshot150 really improved flight time and vibrations on my copter especially under high velocities, and having the telemetry is a great thing that allow to monitor escs health in real time.
Any help is appreciated!