Garmin 645 Music can send to but not receive from mobile app

When I open the Garmin Connect mobile app on my iPhone, it indicates that my watch is not connected.  And indeed, when I create a workout on the phone, it does not show up on my watch.  However, the strange thing is that after I complete an activity, the information from my watch *does* show up on my phone!  (And no, I did not have my phone with me during the activity).  So clearly information is being transmitted from the watch to the phone, but not from the phone to the watch.  Any idea how to fix this!?