So I have had sync problems with my Garmin Smart Scale recently. I haven’t used it for over two years, but now I have decided to start to use it again.
I used the scale everyday for a week, and then when I went to Garmin Connect I realized nothing had been recorded.
After a lot of googling and testing, it turned out that it was my DNS settings at home. I was using Cloudflare as the main DNS (1.1.1.1). When I switched to Google DNS (8.8.8.8 / 8.8.4.4) it all started to work.