In case your backlight strip is not starting video sync when you command it to do so, make sure that:

• Your have the WiZ app version from 1.25.6 or above. Note: if you have paired/set up the Sync box in an older app version, you'll need to delete it and pair it again in the new app version.
• Your HDMI sync box with TV backlight is powered on.
• Your HDMI device (e.g. streaming stick or gaming console) is plugged into the Sync box'es HDMI input.
• (In case you have multiple sync boxes in the Home) You haved selected the right sync box. If not, you can tap below the "sync box icon" in the Video sync page to switch to another sync box.