intensity minutes stopped working

We cannot tell, unless you post some data. Minimally screenshots of the graphs of the all-day heart rate and of the Intensity Minutes.

thank you - the field for intensity minutes has disappeared from my iphone Garmin Connect App. Here is what shows up on my garmin connect imac app:

and this is how it looks for when it was working - from my imac:

And how does the heart rate graph looks for the concerned day?

Here you go 

yesterday:

Today so far

The HR indeed does not seem to be elevated enough throughout the day to give you some IMs. The HR needs to be minimally 10 continuous minutes above ~150% of the Resting HR (90 bpm in this case), to trigger the counter.

How Are Intensity Minutes Earned? | Garmin Customer Support

davebk said:

I had some high HR periods on Sunday and none were counted

I do not see any on the graph you posted. If it was on another day, then please post the relevant graph

davebk said:

More problematic is that the Intensity field has comply disappeared from my phone gc app. I did a hard reset of my watch and my phone. 

If there are zero minutes, the panel remains hidden

Mine did, too. My watch isn’t giving the app a resting heart rate anymore, so the “automatic” calculation of intensity minutes will not work.  You can change the calculation to be based on heart rate zones, but I can’t find how to do that.