If you ever do a
rpi-update on your Raspberry Pi 4, it may occur that the shutdown process do not work anymore as expected, due to the newer firmware version.
The newer version has changed the default “HALT” state after the launch firmware. The default state is now “idle” and “not power-off”. The ethernet adapter will stay active and automatically do link negotiation. That’s why you see the green blinking LEDs.
Open the eeprom configuration:
Look for the following 2 settings and change them as shown:
... POWER_OFF_ON_HALT=1 WAKE_ON_GPIO=0 ...
Now reboot your Raspberry to apply these settings. Then try to shutdown:
shutdown -h now
The Raspberry should now shutdown properly.