Class not compiling after I run yarn build:production but only does on yarn build

So i made this basic SCSS class

.alertbg {
  color: #383d41 !important;
  background-color: #e2e3e5 !important;
  border-color: #d6d8db !important;

that when i run yarn build, it applies it to the element using it, but when i do yarn build:production it doesn’t.

Any idea what could be wrong? why would it work when compiliing on production vs non-production?

I would recommend reading through some of the other posts discussing this same issue: