I and my friends have experienced an incorrect functionality of Garmin Connect modern page: the heart rate graph of some activities uploaded during last weeks, is missing. However, Training Peaks app display the graph as expected.
Heart rate has been uploaded, because the classic version displays the graph, but the modern version of Garmin Connect does not.
Please see attached screen shots and the activity exported from CC.
With Best regards
Matti Purojärvi
Finland
EDIT:Adding screen shots etc....
TCX file: