Check the 'Exclusive' checkbox in TrackIR software to stop it from automatically loading a different profile which could be enabling TrueView.

The Z axis in TrackIR software does not zoom, it moves the viewpoint. The Z axis in ArmA does not move the viewpoint, it zooms. Moving the viewpoint and zooming are very different things and if you want the zoom in ArmA to always be forwards you need to disable TrueView.

Disabling TrueView doesn't disable X and Z axis, it just keeps each axis independent. TrackIR software doesn't have any zooming, it only has translation, so it cannot be expected to behave the same as ArmA. Make sure that you disable TrueView in the TrackIR profile that is being loaded with ArmA.

This is caused by TrackIR's TrueView, it's meant for 6DOF cockpits and not for games like ArmA with independent leaning and zooming.

Turn TrueView OFF.