my Ambientpx setup previously showed that the intensity of the blue LEDs was dropping as the LED was closer to the end of the chain. When displaying pure solid white light this would show as 'warm white' towards the end of the chain. This also happens when increasing the allowed power draw to 2A.
This is a power issue. You need to get more Power to the Farbwerk Nano.
A regular USB 2.0 port can only provide 0.5A, A USB 3.0/3.1 port can provide up to 0.9A.
Changing the allowed power to 2A will not make a difference if the USB connection from the motherboard can only provide 0.5A or 0.9A..
Using the USB Hub of your monitor will not change the provided power from your motherboard USB connection.
You can try an USB Type C connector, that can supply up to 1,5A.
Or you can use a soldering Iron and improve the power delivery yourself