I'm not sure what your object with UID2 is, but apparently it does exist so the ant stops because it has nothing to do.
It found the last path, so failed to find a path is false so it doesn't execute that.
It arrived at the destination but object ID 2 exists so that's false and it doesn't execute that.
It has nothing left to do so, it stops.
+ Zombie1: On Pathfinding arrived
+ [DISABLED] System: [X] Object with UID 2 exists
-> Zombie1: Set Pathfinding acceleration to random(60,150)
-> Zombie1: Set Pathfinding speed to random(60,150)
-> Zombie1: Set AntPosX to random(0, LayoutWidth)
-> Zombie1: Set AntPosY to random(0, LayoutHeight)
-> Zombie1: Find path to (random(0,LayoutHeight), random(0,LayoutWidth))
-> System: Wait for previous actions to complete
-> Zombie1: Move along path