Question regarding ship combat in 1.25 Demo

I have done a search, but I was not able to turn up what I was looking for, so I thought I would ask the knowledgeable user base.

I have downloaded and am running the 1.25 demo. I have a fleet of 7 ships in orbit around a planet, all ships have combat weapons. The attack and defense formation is the “Wall” and attack and defense strategy is “Optimal Firing Range”. The fleet has 67,000 supplies and 3137 ordinance. A single enemy ship enters the planet hex and starts combat. My fleet runs away. After combat I have a fleet of 3 ships in one hex, and 4 single ships in another hex, that is my fleet was partially disbanded.

I try different strategies (Short Weapon Range) and my ships continue to run away in the game. I run the same situation in the space combat simulator and my ships attack. My questions are:
1) Is there anyway to set or see the strategies in the Combat Simulator?
2) Any idea why my ships keep running away?

Other combat situations they seem to be working ok, just in this one case. I have had the same situation at the same planet occur on different turns, that is 4 ships attack, and my ships run away, but when I combat ships in other systems, combat seems to operate normally (that is I chase their ship out of the system, which makes sense given the tactical situation), but it could be the bug in reverse. I have had some successful combats, that is where ships fire on each other. Any ideas would be welcome.

Thank you for your time.