Why I get: Property 'length' does not exist on type 'never'

Question

There is an array of objects in the redux store. When I would get it through useSelector there was no problem.
Then I extracted the code to a util function, and I used store.getState() so then I got the above error.
I've found this post so then I imported the array through args and I've putted in the types of the objects in the array a length property.
Now it works, but I don't like it like this.
Is there a way to get it from store.getState()?
Am I doing something wrong?

Minimal reproducible example, here in codesandbox

export interface MultiQuestionProps {
  ...
  length: number;
}

/* Pass questions as arg, to avoid TS error with length. */
const getDownloadedQuestionsNum = (
  // questionsMultiMixed: MultiQuestionProps,
  
) => {
  const { categoryId, gameTimer, gameType } = store.getState().general;

...

  const {
    questionsMultiMixed,
  } = store.getState().questions;

  let downloadedQuestionsNum = 0;

  if (gameType === constStr.multi) {
    switch (categoryId) {
      case constStr.mixed:
        if (gameTimer)
          downloadedQuestionsNum = questionsMultiMixed.length - indexMultiMixedWithTimer;
        else downloadedQuestionsNum = questionsMultiMixed.length - indexMultiMixedNoTimer;

...

  setDownloadedQuestionsNum(getDownloadedQuestionsNum(
      questionsMultiMixed,

    ))

reducer

interface InitialStateProps {
 
  questionsMultiMixed: MultiQuestionProps[];
 
}

const initialState: InitialStateProps = {
 
  questionsMultiMixed: [],
  ...
  
};