If you turn the bulb on and off five times in a row, the bulb will be reseted to factory default, all the user data including network config will be cleared. I don't think that could help for your case, so please don't do that next time.
The latest firmware update fixed couple potential issue that may cause occasional offline. With that fix, we can't reproduce offline issue in our lab anymore.
What's your dhcp lease duration config on your router?