Incorrect HR values with Spartan Sport + Polar H10

[Dmytro Dashko]

Recently I’ve run 60min competition on the track. While running i saw correct HR readings on the display but after sync I see very strange HR graph which does not reflecting actual HR readings.
HR Zone distribution and Manual 5k splits look correct as it was. but when you look on 1k auto splits it reflects the data from HR graph.

I’m using latest Suunto App and latest firmware on the watch.
HR strap is definately moistured as I did decent warmup before, and I sweated a lot during race.
Here is a link to activity
https://quantified-self.io/user/p5x0xIsM7pUsGvsDGn54jeVrj9o2/event/ba5606ea210450171323267eb886152b39a0208ad5f981a5d8e472c3554d7679