Heart rate reading high plus no hr zone data on last run. All 0%.

Had an odd issue last night.  After run which heart rate data seemed fine thru run, my garmin heart rate measurements after run and through night was reading high and thru this morning.  I did a hard reset and now reading correctly.  I was at manual reading of 50-60 this am.  Was reading into 130-150s.  Then when I checked training zones from the previous night's run, there were no calculated time in zones.  Just -.- or 0% online.  What has happened?  Hopefully corrects itself?  I haven't changed any setting with zones or anything recently.