Power Zone % on workout analysis

I quit quite a few workouts early. For example I use Free Ride 120 to freestyle a workout. If I do a 20 minute workout using the FR120, the Power Zone analysis of that 20 minute WO shows the % time in zone based on 120 minutes, not the 20 minutes I did. So it shows I coasted for 100 minutes and all percentages in other zones are skewed based on 120 minutes. Is that the software or am I doing something wrong. I would like to see the analysis based on the actual time not the WO plan time.