t_t wrote what's your FW version? i think you could power off and power on again to check if the connection is back. I've done so with no luck. It's odd that the bulbs can't hold the Wi-Fi connection...

Model : Hardware Version : Firmware Version : ISP : Installed three smart bulbs in 3 different fixtures and worked fine initially. Now all three have lost Wi-Fi connection. Is this a firmware problem...