Multiple features same Arduino

Hello everyone,
I will be gad if someone can help me with this trouble.

I’m trying to use same Arduino Pro Micro to control two features, as bellow.
- 1 x WS2812B Matrix
- 8 x WS2812B RGB LEDs

I have an external power supply and a GND connection with Arduino.

I have configured both features in Sim Hub and all work fine in test mode but when start a race, in iRacing, only the matrix works properly. The 8 x WS2812B RGB LEDs show aleatory colors.

How can I fix this to use one Arduino Pro Micro to control more them one feature?