So I have had my Fenix 5 Plus for a little over a month now and, just this week, the watch stopped recording intensity minutes even when engaged in vigorous exercise. I primarily use the watch for indoor cycling and have not had a problem prior to this. The watch is recording my heart rate fairly well so I am not certain as to what the issue is. Anyone else have this problem?
Gain access to the user manual. Search for 'vibration'. Follow the instructions.
^I think he's replied to the wrong thread, this won't help you. Have you checked your max HR is still set? I'm not sure what else to suggest. Are you still getting other metrics from it like training status, training effect and intensity factor?