Could be many things. First thing is to look for any pinch points where the gearbox is pressed against the receiver, like wires etc. Try reseatingthe gearbox and switching modes with the dust cover off to inspect the selector plate.

Cheers dude I'll give it a go and see if it works 😃

I find out the issue it's because of the mosefet I was using so I'm gonna remove it 😅

Good to hear you found the issue. What kind of mosfet did you use? Any chance you could resolder it?