Problem with your firmware Android 7

PC does not see a board Rock Pi 4b+ with “maskrom mode”,
I am flashing with the SD card Debian:
dd if=xxxx-gpt.img of=/dev/mmcblk1

Android 9 & Android TV 9 (mo123), Android 10 launches normally (no PPPOe Ethernet).
Android 7 does not start after installation - black screen.

What could be the problem?