I will clarify it really isn’t a bug, but more of a nuisance/polishing thing. Important to state this so you know it’s not an actual bug.
But basically, when creating a new mission, there are two parts:
Select Your Origin - Double Click (needs to be swapped with Single Click)
Select Your Target - Single Click (needs to be swapped with Double Click)
The reason why they should be swapped is because sometimes I misclick towns (on purpose for testing). Those misclicked towns become my target. Swapping single click with double click and vice versa for the aformentioned ones will solve this issue as it prevents me from misclicking towns, and if my Target is AO, I won’t be able to select it as my Origin (the error beep will appear), so there will be less ‘accidents’ so to speak.