Not tracking steps

I had 1800 steps and then went for a walk and used "activity-walking" and it tracked a 1.65 mile walk.  When I hit "stop" and went back to my home screen it was still at 1800 steps, even though it showed my 1.65 mile walk.  I powered my watch off and back on, removed my device from Garmin app and set it up again and still it is only showing 2000 steps (the 200 I've taken since coming back from my walk).  I can't figure out what happened.  Anyone got any ideas?  Thanks!