VO2 Max not tracking even with appropriate outdoor GPS workouts (runs\Bikes)

In Garmin Connect and on my Forerunner 945 my VO2 max has not updated, or logged a run or bike, since April 23.  Since April 23 I have had 13 outdoor GPS runs and 15 outdoor GPS bikes.  It has never not tracked my VO2 max and now it appears to have suddenly started.  Any ideas?