Yeelight JIAOYUE 650 Offline

Dear Yeelight support, I have an offline issues with 2 Yeelight JIAOYUE 650 lamps.

Model: Yeelight JIAOYUE 650 Surrounding Ambient Lighting LED Ceiling Light
Firmware Version: 1.6.6_0056
Server used : Singapore
MI ID: 1744792246

These 2 lamps goes offline continuosly, then come back online. Everything work perfect till yesterday. Then I have also other yeelight ceiling light (480 and 450) and these are working without problem.
Is there any server issue?
Thank you

30 days has passed from my post and no response In the mean time my issue continues. It could be an hardware issue, but it’s strange for 2 ceiling light at the same time, I beat on firmware issue. After reset the both lights everithing work as expected, but after some days I got again the offline issue.

Please Yeellight, is there any beta firmware for the 650 model?? Or can I do something to solve the issue?