using loading utilities inside script setup

[tobystokes]

I can't for the life of me get the loading utilities to work from a <script setup>.

However they do work fine from within a setup function:
✅

<script>
import { useGlobalQueryLoading } from "@vue/apollo-composable";

export default {
  setup() {
    const loading = useGlobalQueryLoading();

    return {
      loading
    };
  }
};
</script>

But this doesn't:
❌

<script setup>
import { useGlobalQueryLoading } from "@vue/apollo-composable";
const loading = useGlobalQueryLoading();
</script>

I can't think of a reason why that 'syntactic sugar' should make a difference, is this expected or known behaviour?