Can’t Reset yeelight ceiling

Occasionally my lamp (Xiaomi Mi YLXD01YL, White) goes offline and I have no way to reset it other than detach and reattach it from the base. Unfortunately I have eliminated the fixed switch that connects and disconnects the current to the lamp. I have already tried with the Quit_factory_app app but have not solved. I tried the reset procedure via the bluetooth switch by switching on/off for 5 times but it doesn’t work!
How to solve?