Simhub led rev lights issue

[Alfred Vistisen]

Hey there
I have two ws2812 led connected to a pro micro, and i can get them to light up just fine
But when it has to move a bit fast between the lights, it starts mixing the colors.
Fx. I have the first 4 diodes to green, and the next two to yellow, but sometimes it makes the first 6 green and completely removes the yellow?? I have used the simhub led editing tool.

I hope you can help