Is this a bug on scrolling animation?

Hi everyone,
Yesterday i made a simple nav bar - bg color change - when scrolling, from transparent to rgba(255, 255, 255, 0.8) worked great.

Today it changes between 3 colors for some reason.

I checked all properties on every element of the nav bar and also tried to recreate the animation again from scratch under a new name etc…

I had this issue in the past but decided to get rid of the animation.

any suggestions?