[Update: Fixed] Galaxy Wearable app is partially broken, preventing new setups from fully working
(Android Police)

Update 1: 2019/04/23 8:42am PDT After roughly six days of not working, SamMobile reports that the login screen has been fixed. If you were hoping to set up your Samsung smartwatch with a new phone, you might want to hold off. The login screen for Samsung Accounts in the Galaxy Wearable app is currently broken, preventing Samsung smartwatch owners from backing up/restoring their watch, downloading apps, and more. When attempting to log into a Samsung Account through the Galaxy Wearable app, the companion application for all of Samsung`s recent wearable devices, only a white screen is visible. Read More[Update: Fixed] Galaxy Wearable app is partially broken, preventing new setups from fully working was written by the awesome team at Android Police.