Intermittent Failure of Accord Nav System?

The Nav system often still works fine, but sometimes the data input for forward motion from the wheels cuts out, so the car icon on the map stops moving forward, but still turns/rotates in response to wheel inputs.

Is there a cable or plug I can check that may have come loose, and where do I find it?

Unfortunately the Nav system does not reference the GPS satellites very often, like current handheld GPS devices do, so it doesn't get corrected (with a jump) for minutes.

I appreciate any help.