If you are seeing a minus sign in the app, instead of a bulb icon for one of your LIFX, please check the following:
- Is the light switch (power) on to allow the bulb to be turned off and on in the app?
- Is your home Wi-Fi network active and have internet access?
- Is the bulb correctly connected to the Cloud?
Turn your bulb off and on.
If it does not reappear after about 60 seconds, try power cycling your router, then the bulb again, and wait another minute or so.
If you continue to have this issue, please contact support.