Question about Philips Hue Play HDMI Sync Box

The picture on my PC comes through fine, but when I connect the Swisscom Box, a picture appears every 5 seconds for 0.5 seconds. Can this be due to the HDMI cable supplied with the Sync box or does the Sync box not work with the new Swisscom box?

I keep getting disconnections of about 5 seconds (black screen) every 5 minutes or so, even with the game console (PS4), even though the bridge is about 5 m away from the Play Box.