Yeelight Color Bulb not working on white

I just started to use a Yeelight Color Bulb that I bought some time ago.
I placed it into my desk lamp and it worked fine for the first 2 days.
After a software update, it only works with colors but it doesn’t work anymore with White and Yellow colours in the “White” panel.
I don’t know what’s the problem since also another bulb has been updated but works fine.

Can you help me please?