One thing I see with each of these 'stuck' events is that you are operating in 'Indian Country' - all the units are involved in the 'action' and there is no apparent attempt to screen their flanks, or to maintain a front-line trace.
These are things that I attempt to do to some extent, and I try to operate my major formations from within my own FLOT. While it is sometimes seen that odd behaviours occur I am overall happy with how the AI plans and reacts.
It might be worth trying - detach a small number of companies and set them to defend at and to the 'flanks' of the unit 'at' its FUP, keep the FUP 'within' your controlled area (you could for example launch a spoiling attack on Eide (?) that was to the rear of your Division attack to form a 'front' protecting your planned grouping).
Simplify the attack planning - a frontal attack in uncertain conditions is far easier to control than a turning manoeuvre. Reduce the angle required to turn - make a wider 'sweep' (not much, just enough to have the move>FUP>Attack in the same sort of direction), or attack obliquely at ~45 degrees, rather than 'across' the front.
Consider giving the 'Division' a defend order, with the task of covering the front line, while the first (and possibly second) Echelon of assault troops move off under their own orders.
A 'divisional attack' is an attack made by a division, not necessarily the only operation it is undertaking, and not requiring every unit to participate... frequently only 1-2 Regts (or 2-4 Bn) will be given initial objectives, with subsequent objectives given to follow-on forces.
Yes something can sometimes go wrong with the planning-execution, but sometimes it is because the order is impractical. If you see this frequently with your play-style then save before you make a major committment. If it gets hung up then send in the 'test-case' and it might be possible to identify what is going wrong with the AI's response to your orders.