Are you rying to squadron jump with a jump engine? The default name for jump engines JMaximumTonnageofShipsJumped(Maximum number of ships in squadron-Maximum Distance From JP)
So the default 1st is J3000(3-50)
3000 ton maximum ship size
maximum 3 size of squadron/tg taken through jp
maximum distance from jp in km.
To jump a tg of 4 ships at once using such a jump drive is not possible, requiring more technology invested in the equipment.
That's the only occasion I can think of that undamaged ships with engines, fuel, crew, not in overhaul and not tractor beamed will not move, even if they are tractored they should move tho iirc, not used one lately. Oh, unless they are in training fleet, but you'd get a popup trying to order them away then.