The one's that preventing you from changing class is going into crafting position, not the menu itself. If you just open the menu, you can change class without closing it.
It's just that when you go into crafting position, then start your craft, you'd still be in crafting position after you finish your craft and the menu pop back on. You need to close the menu to get out of crafting position.
Perhaps SE could make it so that our character automatically get out of crafting position after finishing a craft and the menu pop back on. That way you don't have to close the menu to change to a different crafting class.