Fully inserting the USB connector has no response, but pulling it out slightly shows the default screen, and the problem persists even after replacing the vehicle's HDMI port component. How can this be solved?

This problem usually occurs when a Samsung phone is connected to the product. It is a PC mode peculiar to Samsung phones during screen mirroring. Please try turning off the PC mode feature on the phone, and the normal phone interface will then be mirrored.