Some vehicles end up going around in circles endlessly when given a move order and they pass close to but not exactly over the destination point. Happens when a vehicle reaches top speed and therefore cannot turn tight enough to ever pass over the destination point so it keeps circling around. I noticed this with the Russian tankettes and assault guns.
To reproduce just build a Russian vehicle yard and a bunch tankettes and/or assault guns. Order all of them to move to a distant location and some of them are bound to get caught in the “death spiral”.
I was using rev 936 at the time.