Mining Bug Romanticide

I had a game where drones kept running to the high ground and stopping instead of mining. Rally was set at the mining field on third. I watched replay to confirm. The issue I belive is I had a spine crawler in the middle of my third. MY rally for drones was set at the middle patch. So because they could not go around (the minerals are against the wall) they would run all the way to the high ground (main) and get stuck