i think i actually got a save right before invasion.
https://drive.google.com/file/d/1Eiutf8 ... sp=sharing
-load save
-press 1... move them closer to the planet (more targets for the beam defence)
-press 4... move them closer to the planet. once closer right click invade.
-wait for invade to finish.
-make peace with boskara.
-colony ship arrives a bit later to pickup colonists.

- Screenshot_10.jpg (386.42 KiB) Viewed 199 times
the colony ship can be found a bit to the west when using the game editor after loading the save.

- Screenshot_7.jpg (302.12 KiB) Viewed 199 times
it seems that if i dont declare peace the colony ship swaps to "escape from here" once its at the planet.

- Screenshot_9.jpg (367.97 KiB) Viewed 199 times
if other people also see it with freighters... i think i saw some combat ships arrive at the planet too after peace on "defend" mission or so.
i guess it needs some sort of check if the target of what the ship is trying to do is still a valid target and not i.e. here swapped owner and doesnt belong to you anymore.
maybe a check at a start of a jump? or after exiting a jump? or after a war is over? i guess tons of checks would go on performance again if every ship does some check after a war or something.
maybe there is some command that lists all ships that have the current selected thing (planet) as a target... and then all them could get a order refresh once the targets state changes (i.e. gets conquered) and they then recheck if what they trying to do still works...
well no idea, that is for you guys to figure out... haha