I agree, Maretron might have an update for the GPS to deal with the GPS roll over. Your devices are older and GPS rollover has occurred. The Furuno AIS likely has older software in it as well. In 2020, newer software was released for the FA170 to extend its rollover to 2032. As FishTech says, your main GPS source should be either updated or replaced and I would also recommend getting your dealer to update the FA170 software as well.