Once a plane flies pass the 30m ETE Dest condition of AP+, engaging AP+ while leaving the flight would reset the flight to the 30m ETE Dest position(last save position).
This in itself is not an issue. However, the API would then return the position reports to include the positions before the plane was teleported back to the 30m ETE position after the flight is continued. Leading to the position reports to be duplicated for the leg of the flight that got setback.
Not sure if this is a bug or intended feature as it makes sense to either keep or discard the position reports. It would be good to get someone from the IF team to clarify this.
If this is a feature, it would be good in the future to document it into the API docs.