If you have offline issues with your ceiling devices (ceiling, ceiling 450, ceiling 480 and ceiling 650), please update to the latest firmware and have a try. We have released a new firmware to resolved the issue.
Latest firmware version for ceiling device:
Ceiling - 1.5.5_0180
Ceiling SE - 1.5.5_0026
Ceiling 450 and Ceiling 480 - 1.5.5_0034
Ceiling 650 - 1.5.5_0038
Any questions, let us know!