I have 2 yeelight ceiling lamp. One of them is working fine. The other takes a long time to power on. I have to wait several minutes before the light comes on. After the light came on, powering on and off is normal. But if I leave it off, say overnight, the next morning when I on it it will take several minutes before the light comes on again. The light is brand new and I have updated the firmware but problem still persists. I have swapped both lamps to different room and I can conclude it is not my electrical switch or wiring issue. The other lamp have no such issues.