I will try reinstalling ffh, I guess. The problem started occurring after updating to 3.17 (and moving to the latest ffh patch). In my current game , I am on a continent with 4 AIs, all connected by roads (and the only one that says it is not connected by trade network -- info window -- is the one I am at war with (even though there are roads everywhere, ie, I am connected to their last remaining city). I have "no tech brokering on". But that shouldn't affect resources.