ng build --aot interprets :host pseudo class selector incorrectly

Question

I have using pseudo class selector in my .less css file to change the background color when a product is selected.

:host(.selected .message) {
  background: blue;
}

It works fine with ng build JIT, but doesn't work for AOT. When I inspect the Elements in chrome, for JIT build:

.selected[_nghost-c16]  .message[_ngcontent-c16]{
   background: #8f5f0
}

for AOT build:

.selected.message[_nghost-c16]{
   background: #8f5f0
}

AOT interprets :host incorrectly. what did i do wrong?