Fiddling around with the Plan problem tonight, I finally found the cause of this problem.
In previous versions, when I added a target to my plan, it was automatically selected/turned on/activated. All it needed was a shooting scheme, and it was ready to go. Since 2.4, adding a target has the target de-selected in the plan. One has specifically to select it/turn in on/activate it.
I don't know what the logic is behind this, but, surely, if one adds a target to a plan, it should be an active target, unless one specifically de-selects it. I'm sorry, but I find this to be nonsensical. It's cost me 2 nights of hair pulling!