React JS deleting nested comments

I am studying nested comments functionality in React JS. I have trouble deleting nested comments. Basically every comment has a property replies, which is array of objects (exactly same comment object as the parent ones).

When I try to update the parent state in the inner loop (updateCommentsData(parentStateCopy);) with copied and modified array of objects it throws me this error:
updateCommentsData is not a function even though modified array of objects seems to be correct when console logging it.

Delete function:

function deleteComment(id) {
for (let i = 0; i < commentsData.length; i++) {
  if (commentsData[i].id === id) {
    updateCommentsData((prev) => {
      return prev.filter((item) => item.id !== id);
    });
    break;
  } else {
    if (commentsData[i].replies.length !== 0) {
      for (let j = 0; j < commentsData[i].replies.length; j++) {
        repliesStateCopy.push(commentsData[i].replies[j]);
        if (commentsData[i].replies[j].id === id) {
          repliesStateCopy = repliesStateCopy.filter(
            (item) => item.id !== id
          );
          parentStateCopy[i].replies = repliesStateCopy;
          updateCommentsData(parentStateCopy);
          break;
        }
      }
    }
  }
}

JSON Data looks like that:

"comments": [
{
  "id": 1,
  "content": "Impressive! Though it seems the drag feature could be improved. But overall it looks incredible. You've nailed the design and the responsiveness at various breakpoints works really well.",
  "createdAt": "1 month ago",
  "score": 12,
  "user": {
    "image": {
      "png": "./images/avatars/image-amyrobson.png",
      "webp": "./images/avatars/image-amyrobson.webp"
    },
    "username": "amyrobson"
  },
  "replies": []
},
{
  "id": 2,
  "content": "Woah, your project looks awesome! How long have you been coding for? I'm still new, but think I want to dive into React as well soon. Perhaps you can give me an insight on where I can learn React? Thanks!",
  "createdAt": "2 weeks ago",
  "score": 5,
  "user": {
    "image": {
      "png": "./images/avatars/image-maxblagun.png",
      "webp": "./images/avatars/image-maxblagun.webp"
    },
    "username": "maxblagun"
  },
  "replies": [
    {
      "id": 3,
      "content": "If you're still new, I'd recommend focusing on the fundamentals of HTML, CSS, and JS before considering React. It's very tempting to jump ahead but lay a solid foundation first.",
      "createdAt": "1 week ago",
      "score": 4,
      "replyingTo": "maxblagun",
      "user": {
        "image": {
          "png": "./images/avatars/image-ramsesmiron.png",
          "webp": "./images/avatars/image-ramsesmiron.webp"
        },
        "username": "ramsesmiron"
      },
      "replies": []
    },
    {
      "id": 4,
      "content": "I couldn't agree more with this. Everything moves so fast and it always seems like everyone knows the newest library/framework. But the fundamentals are what stay constant.",
      "createdAt": "2 days ago",
      "score": 2,
      "replyingTo": "ramsesmiron",
      "user": {
        "image": {
          "png": "./images/avatars/image-juliusomo.png",
          "webp": "./images/avatars/image-juliusomo.webp"
        },
        "username": "juliusomo"
      },
      "replies": []
    }
  ]
},