"Call-service error. object of type 'NoneType' has no len()" error out of the blue

Hi all,
I have a light which I use with a custom integration (localtuya by rospogrigio)
I used this integration smoothly without any problem.
Since couple of days I get this error when trying to change color of the light.
Please note that the light turns on/off regularly, I can change the white temperature and light intensity with no issue.
Also scenes works correctly and show different colors, only I can not set manually the color I want.

Any idea?
Also, can anyone please tell me how to log only THIS component cause I have A LOT of localtuya lights, and now I set the debug level in the logger like this

logger:

  default: fatal

  logs:

    #log level for HA CORE

    homeassistant.core: fatal

    custom_components.localtuya: debug

but problem is that I get HUNDREDS of lines and I can not understand which should be useful to understand what is happening…

No one? At least how to log a single entity in logger?