<p>I'm using <code>M80</code> and <code>M81</code> G-codes to power on/off power supply. </p>

<p>Is there a G-code to know the actual state of the power supply?</p>

I don't have this specific printer but this used to happen to me as well on my D-Bot. The reason being bed not being leveled properly. Ensure that your bed is leveled such that the distance between the nozzle and bed is about 0.2mm after homing. Also coat your bed with something sticky like glue or hairspray. You won't need this if you are using a PEI sheet.