App reset after enrolling in je study – Apple Heart Study Review

I installed the app and registered for the study. I received a notification that I’m enrolled in the study a few weeks later. the app worked well for several weeks. However, after recent iOS 11.2 update, the app has somehow reset itself. When I open the app now, it asks me to register again and all my previous data in health app is wiped out. This is a serious bug.
Review by Zpundit on Apple Heart Study.