I updated to 16.28 yesterday, looks good!
Last night, at about 3:30am, I was woken up by my watch when a bunch of notifications came in. I looked at my watch and I wasn't in sleep focus, the Forerunner 970 was full OLED color. That has never happened before. I tried to figure out how to switch it back to sleep focus, and found the focus mode option in the rotary, and when I went there to select 'sleep', it didn't change, and was in 'activity' mode. I gave up, and went back to sleep.
Morning came, and I had no HRV reading, and the watch still thought I was in "activity" focus. Is there something I need to do to get it back to normal focus, and get it to pay attention to my HRV again?