Sometimes it's need to restore you Amlogic Android device like it was before running CoreELEC on it. This can be established by restore the Bootloader environment to default.
If a working UART connection can be established to your device U-Boot console use these commands confirmed by pressing ENTER after each command to restore factory U-Boot environment:
defenv
saveenv
reset
The device will now reset and boot into Android like it was before install CoreELEC.
Place the script aml_autoscript on your CoreELEC boot media on the COREELEC partition by replace the existing file.
Press and hold the reset button when powering the device and the file should be executed and reset by itself.
Afterwards power off the device and remove the CoreELEC boot media.
Place the script cfgload on your CoreELEC boot media on the COREELEC partition by replace the existing file.
Power the device with plugged in CoreELEC boot media and the device should reset by itself.
Afterwards power off the device and remove the CoreELEC boot media.
Do not try to modify the provided boot scripts as they will stop working!