Running Astroneer under Windows 10 Creator build (v 1703). Two truck chassis, one driver, one as trailer linked together. Driver configured with single seat, solar panel, large storage. Trailer configured with 2 large storage. Gathered research items on surface near areas with subsurface tunnels (sorry, no details on location). Had issues with truck driver chassis and trailer chassis merging into each other. Attempted to disconnect them but couldn't confirm success. Went below surface to gather research items, left trucks on surface. When i returned, the trailer chassis had disappeared