Just upgraded to R800XXU1FUB6.
I don't know what changed, but I tell you what has not changed.
When in continuous measurement:
This watch probably has an algorithm that measures the pulse 2 different ways on 2 modes (normal and sport/active).
When in 'sport' mode it divides whatever measures by 2. In 'normal' mode it multiplies with 2.
Well the problem is that the algorithm from time to time fails to recognise the modes correctly.
So sometimes it will guess the mode wrong. So you will have a 'normal' pulse of 64 and the watch will measure 32, or you will have an active pulse of 100 and the watch will measure 200.
It never fails when in manual mode, so it's not a sensor failure.
If all the other measurements (blood pressure, etc) might never be correct, the pulse it's easy. It's done correctly by so many (maybe most) manufacturers.
Such a shame that Samsung fails to do it.
And funny thing is that while they don't care to fix the simple ones, they launch rumours that their next watch will have another sensor: a glucose meter! Ha ha haaaaa