Hi, this should either be simple to fix or impossible to replicate. I just loaded up my game where I am at war with two factions. Checking the diplomacy screen I see that I am getting a relations boost because it says "Outside of Traveling Range". Which is not true (at this point) for either faction.
After I move to the next turn the "outside of traveling range" goes away. But this suggests an exploit that could be used against the AI.