If the video is abnormal when using the HDMI IN port, please follow the below methods to do the troubleshooting:

1. Check whether the TV works in the right input mode. If the device connects to the HDMI1 port on the TV, switch the TV to HDMI1 mode.
   
2. Change another HDMI cable to connect the device to the TV if you have a spare one.
   
3. Change another HDMI port to connect the device to the TV. Please note that it requires plugging the device into the correct port with the HDMI 2.1 cable if you play the 8K video.
   
4. Change another device to connect it to the TV if you have a spare one.
   
5. Try to restore the TV back to the factory settings: press the Home   button on the TV remote. Then select Settings-->Device Preferences-->Factory Reset.
   

If the issue cannot be resolved, please feel free to call the TCL hotline for further help.