wrong % body fat in Index S2

In the last months I read that the wrong measurement of the body fat was solved.
I buyed yesterday the Index S2 (sw version 3.30).
Tanita showed a body fat 18,3.
Garmin S2 shows  a body fat 27,3.
I think that S2 is wrong and also I ... was wrong to don't listen the lot of post on this Forum against Index S2.
I am very disappointed!!!