Disable AI reacting to far away combat

[eBakedPotato 0]

Hello. I am on the process on making a mission about clearing the hills northeast of Morton, with US forces meanwhile guarding the city with some checkpoints (with Defense waypoints) and patrols.

However, when a firefight starts on those hills, the US forces on Morton change their status from "Following orders" to "Autonomous", ignoring their waypoints and reacting to the combat. Once everything is secure, they go back to their original task and to "Following orders" status.

Any ideas (I think the only way is by script) of how to make them ignore those firefights? Danger Event Range doesn't work, and their waypoints are pretty small too.