Arctic Liquid Cooler III Pump Cap has 1 red led always on

Hello,

I have a led that always stays red even if I paint it black. All other leds are ok.

I have tried with the Arctic Liquid Cooler III device in Signal RGB and also made a custom 12 LED string and it always behave that way.

If I close Signal RGB, the led will turn on, If I use another software ( open RGB ), I dont have that issue.

Any hints ?