The product connects to the head unit normally, but when the rear screen is connected via HDMI, the rear screen shows a black screen.

1. Reset the product and check for updates

2. Check the head unit settings according to the rear-screen connection videos

Video ① https://youtube.com/shorts/amXbKgrQXeE

Video ② https://youtu.be/0bSB_584RLc

3. Replace the HDMI cable with a different one