"Yesterday" + "Last 7 days" show loading error

Garmin Connect Web shows the following error in the "Yesterday" and "Last 7 days" section of my homescreen.

Loading Error

We had a problem loading this feature. Try refreshing the page or checking back later.

Refreshing and checking back later (even after 1 month) did not work.

By contrast, the Garmin Mobile App shows the proper values.

What ist the reason for this?