The last 2 runs I’ve been on with my 965 I noticed that my HR didn’t get higher than 130 when I was doing a tempo run or running up a hill hard. For the tempo one I noticed at the end of the run and thought it was a one off. For the hills I noticed it again and tried to fiddle around with pausing the activity and resuming later, then as soon as I went back into it the HR was showing the true HR. This has only started happening in the last couple weeks so I’m wondering if there’s a fix for this bug or if Garmin are aware and working on one?