Yeelight Ceiling Light installation - no light???

Anyone has any good troubleshoot tip for installing yeelight ceiling lights? I had both N & L wired correctly & checked there’s electricity passing through, but even with the wall switch on, no light. Tried the bulb to other connector, the bulb worked fine. When I installed my first yeelight, same issue, but some fine day, when we reconnect, it works… (Singapore) instead of waiting that “fine day” to appear for this 2nd installation, hoping some souls have good reco…

Having same problem with recently bought lamp - it works while connected to wall socket, but not when attached to ceiling. All things are checked and I ran out of ideas.

That is not really logical.
And the only logical thing coming to my mind is that you cut your wire on the ceiling while making a new hole.
Check if you have voltage in your wires with multimeter.
Good luck.

Now I got what problem is - bad contact when lamp attached to ceiling. When lamp attached to ceiling, it looses contact with unit where wires attached to due to its weight. Bad design.