The 138,000 cubic-meter Excalibur tanker, from Excelerate Energy's fleet, was seen still docked at the terminal on Tuesday, the data showed.
It was not clear if the tanker was offloading or loading at Freeport, which can reexport previously imported cargoes as well as import LNG.
Freeport LNG was not immediately available for comment.
The terminal received its first cargo in 11 months in July, and there has since been speculation of potential reexport deals being mulled.
Reexport is an increasingly favorable option for customers at Freeport as U.S. gas prices languish way below prices in Europe and Asia.
ConocoPhillips (COP.N) and Dow Chemical (DOW.N) have import capacity at Freeport.