Agree with RF, major bummer!
I've not yet tried to have S2 follow me on my bike, but that could happen to any of us unless we know an area very well or if minimum flight level (height floor) is engaged at a level higher than any foliage/sticks.
So the question is, how reliably does S2 stay at minimum flight level above ground when the terrain undulates? Did you have this set? That stick seemed like it was about 7' tall, the default height floor is 8' per what I've seen. Unfortunately it looks like we cant chnge the floor setting...seems like a shortcoming to me.