I’ve seem similar posts, but think we have a different issue.
both my wife and I are long standing Garmin Connect user. I am connected to the scale, and have invited my wife. When she clicks on the email link and signs in to Garmin Connect on the web (does not open the app), she receives an error message “Looks like our laces came undone. We will be back up and running in a few moments.”
We assumed part of Garmin services were down, even though we have no problem syncing watches to Garmin Connect and I can connect when weighing in on the scale. This has been the case for a few days now, so hoping someone here has an answer.