Yeelight JIAOYUE 650 like a strobe on 100 Brightness.

Hi everyone, I have 3 Yeelight JIAOYUE 650, one of them has been working for a couple of days in a particular way.
If I set the main light brightness to 100%, the light looks like a strobe, while if I set the light to 80% the light is stable and steady, regardless of the color temperature.
I tried with a reset, I installed the latest version of the software and I tried to place it on another “base” but nothing works.
There is any way to fix, to do an hard reset or a clean install of the software?

Thanks.