Sunrise/Sunset Complication on Apple Watch no longer works

Sunrise/Sunset Complication on Apple Watch no longer works, after the last ios update.

In detail: the Complication does not show the time in the quadrant. However, it is possible to tap on its icon and get the correct information in the new window. Possibly, it opens the Complication app.

The support could not tell me if this is a new feature of the ios update or if it was a bug to be resolved.

Support suggested unpairing the Watch from the iPhone, but I declined to go down that painful route.