I had the same problem, had seen this post before, and wanted to say what I did to fix it. I just wiped data from settings > apps, and then uninstalled it from there as well, leaving the framework. Once the app was gone, I just reinstalled it from the Play Store, and it let me use it right away. Just wiping data made it go from being stuck at iris scanning / fingerprint (depending on which one you are using as the main) to being stuck connecting at the rewards tier screen right when it first loads. But uninstalling it worked for me, YMMV of course.
