When I group multiple units and put them into a formation, I can sometimes right-click and drag my mouse and the end position of the whole squad is fixed and they will all move together properly. Sometimes however, right-click dragging resizes the group and I have to resize the whole squad and the formations falls apart.

Can anyone tell me what is happening and how I can switch between different modes.

Also, when I click on a location top move a group how can I be sure that the squad stays facing the correct direction. Sometimes they seem to move and face different directions depending on which way I am facing.