It seems that the calibration and dead zone settings don't work correctly.
As soon as I launch and have flight control I get reverse acceleration and have to put slight forward pressure on left joystick to stop that.
I have tried recalibrating and centering and also using the gui to set a larger deadzone (even to the point of a complete deadzone) on the y axis, but it has absolutely no effect in game.
I also tried setting a larger deadzone for the x axis, but that didn't work either.

I have a Galaxy S8 and a genuine XBOX ONE controller, both with the latest firmware. This problem only occurs in VO, both in normal and VR versions. It does not happen in any other games that I have tried.

I will have a look at the config.ini file tomorrow to see if it is just a GUI issue.

I don't think the GUI for controller calibration actually works on Android. Here's a thread from a few months ago: https://www.vendetta-online.com/x/msgboard/1/34446

You will probably have more luck in changing the deadzone settings in the config file, but I do know that others have had issues with xbone controllers, mainly with the way the triggers are treated (this may have been fixed?) but good luck sorting it, without a controller VO on mobile is quite horrid :)

OK, so after some time trying various things I have concluded that the GUI and the config.ini reflect each other. Change either one and it changes the other.
However, those settings, no matter what they are, do not change anything in the game.