Hello @gerchris,
Since the last update, it is possible that some customers are experiencing problems with HDMI, such as black screen, pixelised image or no sound. Our technicians are working on it, however, we cannot give you a resolution date.
Do you use the new HDMI cable provided with the UHD box? Have you tried different HDMI ports?
We advise you to use the WLAN kit if it allows you to watch Live TV.
We are sorry for the inconvenience and thank you for your understanding.
Kind regards,