You increased the range of the MORTAR goal. But you have to increase the range of the AMMOCAB goal which is only 1250.
AMMOCAB_main_ammocabinet =
{
CreateOnLoad = 0,
GoalType = "AMMOCAB",
Position = Vec3(1512.000, 939.000, 516.000),
Range = 1250,
TeamAvailability = 6,
},