Why is `isMutating` positive once `onSettled` is called?

const { mutate: handleReaction } = trpc.post.handleReaction.useMutation({
  onMutate: async () => {
    console.log(
      "onMutate isMutating",
      utils.post.handleReaction.isMutating(),
    );
    startTransition(() => {
      if (onReaction) onReaction(reactionTypeId, emoji, emojiName, isReacted);
    });
  },
  onSuccess: (data) => {
    console.log(
      "onSuccess isMutating",
      utils.post.handleReaction.isMutating(),
    );
    if (utils.post.handleReaction.isMutating()) return; // Prevent query update if there are in-flight mutations
    console.log("updating");
    utils.post.getPostReactions.setData({ postId }, data);
  },
  onSettled: (data) => {
    console.log(
      "onSettled isMutating",
      utils.post.handleReaction.isMutating(),
    );
  },
});