Navio 2 is reinitialising after arming

I am running a custom firmware of arducopter in my navio 2
Everything has been set up and the drone is ready to fly but every time I arm the motors start working and then suddenly stop and the autopilot reinitialises after some seconds

The drone is a octo quad
I am using a 3s 25a 5200mah battery
8 t motor motor
8 cyclone Bl-heli s esc

I have tried everything I know but this issue won’t fix
Could it be the battery being too small ?

Without any details it could be anything.
Provide all details of the used hardware and software of all major components.
Provide a log.bin file of your flight test

Wouldn’t it be a better plan to complete the build and tune with official stable firmware, if there is such a thing with Navio, before introducing a custom version?

I did that already

I will also add that in this build we added a smoke stopper to prevent short circuit.
Could it be the issue?

I haven’t done a flight test with the custom firmware
Although it basically the same as a stable arducopter firmware we just changed very few things

The frame of the x8 drone is flytrone from AliExpress with 8 cyclone bl-heli s motor, 8 1700kv tmotor. 7 inch props, holy bro telemetry and a tcp 3s 5200mah 25c battery

No idea, never used one.

It sounds like you are demanding too much of the power system. That battery sounds extremely weak for an octo configuration…

thank you for the response
I will add another battery in series and remove the smoke stopper

In series? What are your components rated to handle? Did you want a 3S design or 6?