All units (most noticeable on vehicles) consider a movement order in the queue (nonfinal, initial or intermediate orders only) by shift+ordering complete within a large distance of the actual order point.
This causes huge issues with micro and a frustrating lack of control over vehicles. While not a bug per se (depends on developer intent), it's a mechanic which creates behavior that feels very buggy and takes the controls of the game away from the player. I suspect it's also to blame for many complaints people have about pathing in general.
Say I want to get my Sherman to do a u turn around a small house while going forward (so I don't have to decelerate to reverse out or because I've got other tanks coming up behind him, any number of reasons). I shift click about the front of the house and then shift click behind. I then quickly select my other tank to prepare him to come up the rear, or click away to retreat a dude somewhere else. The Sherman is liable to halt, consider that order complete even though he didn't get anywhere near the intended location to the front, and stop to reverse, perhaps back into the other tank I had coming up or perhaps affording time for that AT gun to deliver another shot. It forces players to babysit units without any justification, and hinders their ability to multitask.
This extends to facing orders. Say one wants a vehicle to face a specific direction before shift-reversing out, because he knows it would path smoother, or get away faster, or safer. He orders it to face towards the AT gun, or face parallel to the pathing blocker he intends to go around. Instead, this same "Queued movement order complete within radius" bug will interpret the facing command as complete whenever the vehicle is within a given distance of the point it was ordered to face at, and will attempt to path to the next ordered point without completing the intended facing order.
Edit: this behavior is present on all units (just tested with Raketenwerfer) and on infantry (I tested with riflemen) as well. Presumably it's intended to make the gameplay and pathing feel smoother (don't have to go all the way to displayed cover points if you're just gonna order them to move again when they all get into place), but the detriments these training wheels create do far more harm than good.
Edit 2: In the spirit of Cuddletronic, thanks
Edit 3: Just realized that "Major" in the title may be mistaken for USF major. Mods change if u want