Your runs and Apple Health
My run shows 0.00, with no distance
Some watches write a run to Apple Health before they write its distance. Why Not reads the run again at every sync for seven days and fills the distance in as soon as Apple Health has it.
If the distance never arrives, the watch app did not write one for that run. The run keeps its time and heart rate. A run with no distance shows no pace and no share card, because there is nothing honest to show.