That's the main reason it hasn't been fixed. The Devs are having a hard time tracking it down apparently. If it was reproduceable it would have been fixed by now.
Best thing you can do is follow the steps in the thread below. Also if you're playing just with your friends, try playing in the developer.exe. Even if checksum logging is off it maybe able to generate a small Sync Error/log that might help the devs.
https://forums.sinsofasolarempire.com/422197