So, this is probably not literally a bug, but:
I made a small ship, gave it a captain, outfitted it with two mining lasers and let it roam free mine in a system with a large asteroid field, thinking this would be a nice way of gaining some materials without having to mine it all myself.
However, then I decided to explore a bit while it did that, but I noticed that once I got one or two systems far my income of iron stopped.
Concerned, I headed back to the system ("did it get attacked by pirates or fly into an asteroid?" I thought) and as soon as I got there it started again.
I assume this is because (logically) systems stop getting simulated once you're not there, but it's kinda odd and de-immersing when it's mining it's doing.
Maybe some kind of approximation could be made for remote miners? X of whatever metal is in the system per second/minute, with X based on the asteroids in the system, mining gear and ship speed? That way you can give the illusion that your ships are still doing their work remotely without actually having to do anything but calculate one number and then add something to your materials regularly.