Combat problem...

[Dragon of the void]

Just a thought:

I think you already checked that there are no fleet commands (no fleet).

Are your ships refits of on older "direct fire" design that was/is set to "optimum" distance ?

I read somewhere in here (and it confirms my own observations) that refits still hold the strategy of the OLD design;

You test with simulator, and get perfect results (correct orders, no refit), but get beat in real combat (old, incorrect orders still lingering).