Ships not attacking planets

Check your treaties. ANY treaty with ANY race that prohibits planetary bombardment, then NONE of your ships can attack planets.

I had this exact problem. I think it has something to do with stratgies or something. Basicly, i just changed all my ships to "point blank" and gave them extra sheilds and armor, and just had to deal with some incidental casulties! But ironically, with all your ships rushing in together, you actually wipe everything out way faster. Point blank FTW!

Let's go

Another thing is if you attack planets while you have a ship with cargo space carrying troops/fighters and the capture planet strategy.

I also agree that the problem could be related to treaties.

I have run into AI players who use ships mainly with Ripper Beams in weapon mounts. In those cases, point blank is suicide unless you have equally armed ships with better shields/armor and/or more/better Ripper Beams/mounts then they have.

The engagement range of strategies has no effect, afaik, on whether or not a ship will go after a target. (Unless it is actually set to an effective 'do not engage')

Many weapons do more damage at closer ranges, and accuracy decreases at longer ranges, so weapons are more accurate at closer ranges, which is why battles are shorter lived up close. The extra shields and armor is a good idea, since it means the enemy will also be able to do more damage more often.