When the Radio control is turned off, the server on the aircraft will act on its own. Is this normal?

ArduPlane Plane 4.0
1

The firmware version of my drone is 4.05. I use different flight controllers,(Pixhawk and Pixhawk cube) but the problem is the same for both aircraft.

2

Are those servo outputs setup as RC pass-thru ?

3

Don’t know if it is the problem of interference?

4

Yes, it could be. Make sure your cables are as short as possible. And that no transmiters are in their near.