Yes, only the HDMI is connected, without lcd. With Android 7 it looks like double vision, and the touch screen does not work correctly due to the bad vision of the icons on the screen.
I am using the nanopc t3 plus with its 10 inch hd101 screen. But I have some clients who have asked me for the option of putting larger screens, 12 inches. I have seen waveshare hdmi + touch screens (usb). You should change something in the android configuration for those screens to work correctly. ...