Today, the USB-C to HDMI adapter for DeX arrived. I connected my Bluetooth keyboard and mouse to my S9 and connected my S9 to my TV which uses a 1184x768 resolution. DeX loaded and I was then told to check if four corners fitted into my TV and if they didn't I should try changing my TV's settings. The corners went off screen a bit and there are no settings on my TV for changing the screen. What should I do?