I know absolutely nothing about how you are programming this (!), but it looks like a range? If so, can you change it to just a specific 1 x 1 X,Y square, and try crossing that space to see if anything happens.
At least you would know that basic code is working correctly, and as you expect.
This would be a doddle in LFSLapper ('lapper')!
I'm so used to;
RegisterAction (e.g. Node or Zone), track, X, Y, size, sub-routine_name
e.g.
RegisterZoneAction( "AU1" , 52,-899, 3 , PitLaneSub,"" );
Sub PitLaneSub
IF {action occurs - eg enter specified Zone}
THEN {do something}
ELSE {do alternative something - even ignore ELSE if no alternative}
ENDIF
End sub
Apologies, if nothing here in this post helps.