Is there a way to force non-combat ships to stop "Evading hostile fleet"?
Set their behaviour to passive.
You can change a fleets behaviour in the fleet window (bottom left), can't provide a screenshot right now, but should be easy to find.
There are three options:
- aggressive: fleet automatically attacks hostiles
- passive: fleet won't attack on its own, but will defend itself
- evasive: fleet retreats as soon as enemies appear.
non-combat ships are on evasive by default and as such they will run immediately, when a hostile is in the system. I recommend setting them to passive while exploring, but evasive, once you get in a war.