Why does this SCSS result in a no-descending-specificity error?

This small SCSS block

a {
  color: red;
  &:hover {
    color: green;
  }
}

i {
  a {
    text-decoration: none;
  }  
}

Gives this error

Expected selector "i a" to come before selector "a:hover" no-descending-specificity

But if I reverse the order

i {
  a {
    text-decoration: none;
  }  
}

a {
  color: red;
  &:hover {
    color: green;
  }
}

The error just reverses too

Expected selector "a" to come before selector "i a" no-descending-specificity