Lidl SKHK 40 A1 Bluetooth Headphones Not Working

Hello, I bought a SilverCrest SKHK 40 A1 headset at LIDL, which worked perfectly for a week. Overnight, after charging it, when I turn it on, the little purple LED lights up and goes off after about ten seconds, but there is no sound and the Bluetooth search, characterized by the flashing LEDs, does not start! Do you have a solution to this problem? Thank you in advance.