Just downloaded the update today and went for my first run and after the 3rd of 4 interval runs in heart rate zone 4 it went as normal to the 1.5min cooldown then back to the 4th and final interval run and I noticed the HR reading was still in Z4 where normally it drops to Z2/3 during the rest period.
So I started walking and it was slowly moving around and after 1.5min it just instantly dropped to low 120's and I had to sprint to get it back to Z4, missing over half the 4min interval.
On the walk home the HR was abnormally high (150+) and it would not drop. Same when at home and rested. I restarted the device and it showed my normal/expected rest heart rate again.
Never had this before this update.
