Narrative:

While on approach to ZZZ from the zzzzz transition to ZZZZZ1; approach control advised us that we were off course. Autopilot was engaged and flight directors were following the magenta course with LNAV - VNAV path. We looked and saw that the course had a curve just outside of ZZZZZ1 to intercept instead of proceeding direct to ZZZZZ1. We had no indication in the aircraft that this wasn't normal for the FMS. If I were to guess; I would say that the difference was between .5-1 mile north of ZZZZZ1 with the intercept. The controller told us to take a look on the ground. I did reprogram the FMS with the arrival and approach in the FMS on the ground; and found nothing out of the ordinary. On descent to ZZZ we were given many different altitude and speeds that were faster and lower than the STAR. I don't know if that had anything to do with it. In summary; we didn't see anything out of the ordinary from a cockpit perspective; but after looking at flightaware of our flight and the flight after us; we could see a difference in the two. We did talk to the crew that flew behind us and asked if they were coupled with the autopilot as well to try to figure the difference with the ground track. They were doing the same thing as us; but the software between the aircraft had different outcomes.

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Original NASA ASRS Text

Title: Air Carrier Pilot Crew reported while using the autopilot; ATC informed them the aircraft was off course.

Narrative: While on approach to ZZZ from the ZZZZZ transition to ZZZZZ1; Approach Control advised us that we were off course. Autopilot was engaged and flight directors were following the magenta course with LNAV - VNAV PATH. We looked and saw that the course had a curve just outside of ZZZZZ1 to intercept instead of proceeding direct to ZZZZZ1. We had no indication in the aircraft that this wasn't normal for the FMS. If I were to guess; I would say that the difference was between .5-1 mile north of ZZZZZ1 with the intercept. The Controller told us to take a look on the ground. I did reprogram the FMS with the arrival and approach in the FMS on the ground; and found nothing out of the ordinary. On descent to ZZZ we were given many different altitude and speeds that were faster and lower than the STAR. I don't know if that had anything to do with it. In summary; we didn't see anything out of the ordinary from a cockpit perspective; but after looking at FlightAware of our flight and the flight after us; we could see a difference in the two. We did talk to the Crew that flew behind us and asked if they were coupled with the autopilot as well to try to figure the difference with the ground track. They were doing the same thing as us; but the software between the aircraft had different outcomes.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.