BTW, this "No planetary bombardment" clause is also breaking combat.
I figured out why my missile and gun ships were fleeing. At first I thought it was because they had no targets against a poorly defended planet (only fighters and weapon platforms). What I finally found out is:
"No planetary bombardment" clause in effect:
- Planet with ships, fighters, stations, fighters, NO weapon platforms: missile and gunships, fighers attack the space defenders, dropships rush towards the planet.
- Planet with or without ships and stations, with fighters AND weapon platforms: missile/gun ships and fighters disengage and flee, dropships do their job.
"No planetary bombardment" clause NOT in effect:
- Planet with or without ships and stations, with fighters AND weapon platforms: missile/gun ships and fighters attack the space defenders, dropships rush towards the planet.
So, this clause makes it so your missile/gun ships and fighters won't even attack the enemy space forces (ships, stations, fighters, satellites) if there is at least one weapon platform on the planet. And this regardless of the TF orders, whether they are escorting a dropship or in their own TF with "Max Weapons Range" orders.
I believe there is a way to exploit the AI too if it fights along the same rules. Just in case it has such a clause in one of its treaties, make one tiny weapon platform. All his space forces but the dropship will be disabled during the invasion. If the AI can capture planets that is

.