HR Data - Inconsistent

I apologize if this has been identified already.

I stopped using the new 'Upload' feature because I found that the HR Data was never correct.  If I did an hour workout, it would only show maybe half that time broken up into various zones.  I know my HR was not below my lowest zone, or above my highest zone for half the time.  If I took that same workout and uploaded using the 'Import from Garmin' the data was correct.  So that's what I have been doing.

However, yesterdays workout was a 1:52 run.  When I look at the HR Data it shows almost 3 hours of time in various zones.  I did stop at a couple of lights, but that added maybe a few minutes.  Something is just not working right.

Am I doing something wrong, or is there a bug?