One piece of information that may help here.
If I open the side bar & choose regatta setup, then select a mark to edit, now the controls work correctly (but pinch zoom doesn’t work – but then it doesn’t on the Cesium web site either).
It continues to work OK when I close the side bar and FOR AS LONG AS I DO NOT PRESS ANY OF THE RACE PERSPECTIVE BUTTONS. Once I press one of the perspectives (fleet, course view, helm view etc.) things go wrong again.
Regards
John