In case your video source is playing 4K when connected directly to TV but dropping to 1080p when the Sync box is added, try to switch off the Sync box and switch it on again. The video resolution should go back to 4K resolution.

The reason why it's happening is because the TV is turned off while the video source device and the Sync box were still on.

• In normal situation when the TV, the Sync box and the video source are all turned on, the video source device would receive the EDID (Extended Display Identification Data) from the TV and output the video format supported by the TV. (The Sync box would pass through 4K signal)
• In the situation where the TV is turned off while the video source device and Sync box were left on, the video source device would receive the EDID from the Sync box and output the video format supported by the Sync box, which is 1080p.

To prevent this problem from happening, try to turn off the video source device connected to the Sync box before or at the same time with the TV.