IAchievement.percentCompleted rounded to int

I am using Unity's Social API on iOS to report achievements.

As far as I can follow the documentation trail, using this:

 Social.ReportProgress( "AchievementName", 2.6f, success => {})

should work, as the second parameter is a double on both the Unity side and the Apple side.

But, when using Social.LoadAchievements() to retrieve the achievements back, the saved value lost its precision and is rounded down to 2.

Does anyone know why this is happening, and is there a workaround (without resorting to locally storing the remainder of the value...)

There is a similar question on StackOverflow and on the forums, both with no answer.

EDIT: There is an old thread on the Apple developer forums that hints that this is an apple issue. Does anyone knows if this is still the case?