I have two TZ MFD's that are on the system with a new NAV pilot 711. I have tried both Precision and Economy modes but when the system is following a route it consistently does a 4 degree swing to starboard, no matter the mode, when engaging the next waypoint. The ruder sensor appears to be on correct alignment (goes straight when reading 0 degrees) and the latest software has been installed by my installer. The result of this swing is to take our boat out to 120 to 260 yards and then brings it back on track, faster in Precision mode and more slowly in Economy mode. Is there any way to stop this swing to starboard?