`scss/function-no-unknown` doesn't work well with local `@function`s

[TomONeill]

@function get-color() {
  @return #333ccc;
}

.element {
  color: get-color(); // Unexpected unknown function "get-color" (scss/function-no-unknown)
}

It is not unknown; it is defined right above it.

I did add this to my stylelint config as the readme of the rule states:

{
  "rules": {
    "function-no-unknown": null,
    "scss/function-no-unknown": true
  }
}

Am I misunderstanding this rule?
I would not expect this as this is the scss version of this rule, which you'd think takes the functions within the same file into account.

I am on version 6.12.1.