Question about Philips Hue Gradient Signe

Hello all, I unpacked the lamp, connected it to the power supply and... Nothing happened. Checked the cable, connected the power supply to the cable, put it in the socket and still nothing. With my first lamp, the light came on immediately and the bridge recognised it straight away. In the meantime, I reset the bridge, changed the location of the lamp, changed the socket, nothing. Do I really have to send the part back? -.- Greetings Simon