intensity minutes for tennis activity doesn’t add up

Can you share a link to the tennis activity, or a screenshot of the Intensity Minutes values on the Stats tab of the concerned activity? You have to scroll to the bottom of that screen. And also a screenshot of the Daily Timeout graph on the Intensity Minutes screen for that day.

Here the statistics sreenshot you asked for. I also provided 2 other screenshots where the previous activities were just “walks” and even theses 2 were not very heavy they count! Normal minutes and intenses ones. For the tennis activity none appear… so I don’t get any minutes at all when the activity type = tennis. That was not the case before.

Here other screenshots of tennis activity that were used to produced minutes (in February) before I moved to the Beta version 

lou_e_roy said:

Here the statistics sreenshot you asked for.

You have to scroll down to the section Intensity Minutes - they are at the bottom of the page. If there is no such section, then it means that your watch does not show these values in the activity statistics. However, as I wrote, there were practically certainly no Intensity Minutes earned during this activity, since the heart rate was too low.

lou_e_roy said:

I also provided 2 other screenshots where the previous activities were just “walks” and even theses 2 were not very heavy they count! Normal minutes and intenses ones.

That's very well possible, of course, if the heart rate was elevated above the threshold during more than 10 continuous minutes.

lou_e_roy said:

For the tennis activity none appear… so I don’t get any minutes at all when the activity type = tennis. That was not the case before.

Again, it is very well possible, it the heart rate was elevated above the threshold during more than 10 continuous minutes, at those previous tennis activities.

Please read the article How Are Intensity Minutes Earned? | Garmin Customer Support - it will help you understanding how it works. 

My issue is that I don’t even get ‘moderate’ minutes neither…

It is the same principle. To get "moderate" Intensity Minutes the heart rate has to be elevated for more than 10 continuos minutes above approximately 150% of the 7 days average Resting Heart Rate. To get "vigorous" Minutes the threshold is above roughly ~200% of the 7 days average Resting Heart Rate.  

I have to repeat - please read the article How Are Intensity Minutes Earned? | Garmin Customer Support - apparently you have some mistaken ideas about the way it works.

The French version may be perhaps better comprehensible for you:

Comment l'option minutes intensives fonctionne t-elle ? | Garmin Support

Thank you. Given the explanation on the web, I think I got why I don’t get any minutes at all. On some Saturday we’re 4 players on 2 courts playing continuously. So the 10 minutes is easily achieved. In some other Saturday we’re only 3 players on a single court doing round robin. In this situation I guess the 10 minutes isn’t achieved given I have to sit down while my the 2 other players have their time. Thanks for your assistance.