Fitness Age in GC?

Check the paragraph "My Device Supports Improved Fitness Age, But It Is Not Displaying One or Updating" in the document What Does Fitness Age Mean in Garmin Connect? | Garmin Customer Support

Already checked:

Resting heart rate 

Body fat percentage, or height and weight  

A gender selection of male or female  

Stale weight data  

I just wonder if another key data is missing in my profile (but not mentioned in the support article), so that's the reason I've resorted to posting my question on the forum.

Is the weight value really recent? I mean did you enter a new value (even if the same as previously), in the last 7 days?

Yes, it's recent. Last time it was updated yesterday. And over the last week I was weighing and entering values daily just to make sure weight is always 'recent'.

Was the Fitness Age never showing up, or did it disappear recently? Did you check it both with the GC Mobile app and with GC Web too?

It was never showing up and I checked the both Mobile and Web GC.

For the context, I was Instinct user for a couple of years and Instinct obviously did not support Fitness Age. About 1.5 months ago I've upgarded to Enduro - removed old Instinct from GC, added Enduro, ensured Endure was the default fitness tracker. I got all new features and reports supported by Enduro, like Training Status, Respiration, Sleep Score, HRV Status, Vo2Max, Lactate Threshold, everything except Fitness Age.

I tried removing and re-adding Enduro in GC a couple of times with no luck.

Yes, strange indeed. The old account with Instinct is certainly not the problem - I had one too, and see now the Fitness Age anyway (though with Instinct 2, not with Enduro), without even removing the old Instinct (just retiring it). Well, normally VO₂max should not be needed with the new system, but do you have a value populated in the VO₂max report?

Yup, I have Vo2Max report and it's updated almost daily.

Hm, I am afraid (unless someone else peeks in with an idea) you will have to contact the Support, and have them investigate it.

Hm, I sniffed some API requests and https://connect.garmin.com/fitnessage-service/fitnessage/ returns vigorous minutes and days as stale.

Though Intensity Minutes report over the last week shows vigorous minutes 

Any ideas why vigorous minutes/days are deemed as stale? Also Intensity Minutes report above does not seem to take into account the timezone I'm in. All those "jumps" in intensity minutes should occur at the start for the most of days (when my morning runs happen).

Wonder if due to the timezone difference intensity minutes are always stale.