When I went to https://healthmate.withings.com/999818/weight/list
It just endlessly reloaded the same page. (the three dots moved for a while, then page reloaded)
I tried a few links on that page but they all did something similar.
It was doing it for a few days, so I came here to fix it .... funnily enough the act of verifying my email address so that I could post this fixed it, but I bet 90% of the customers wouldn't figure that out as the reloading screen doesnt ask you to do that !