If the alarm isn't switched off, the light will go off about 10mins after the alarm time. Just to stop it being on all day. Could it be that, now you don't have to actively switch off the beep noise, you're not switching off the alarm (i.e. pushing the button in). That would explain why the light goes out shortly after you wake up. If it's not that then please give us a ring on 01954 780500. Thanks