NetworX Panels arm in stay mode

Have NX8 and smartthings. Have pro panel with output 2 set as momentary button with 2000ms duration, arms and disarms in Away mode perfectly. Have output 1 set as momentary button and have tried various durations of 250ms to 1000ms, will not arm panel. If set to 1500ms and above panel only arms in Away mode. Has anyone figured out the Stay mode arming on these Nx panels.