Sudden Decrease in Intensity Minutes

I've been tracking my Intensity Minutes on my Venu 2 Plus for the last three years.  In all that time, I've almost always made my target goal.  Now, in the last month or so, it seems I'm unable to reach that goal.  My workouts are the same.  My exertion levels feel the same.  I haven't changed any settings on the watch.

Has anyone else noticed this? Has anything changed on the Garmin end with their software?

Thanks, Leon