Custom post meta values are null despite setting default values

[pdewouters]

I have registered a meta field:

      register_post_meta(
        $type,
        $meta_key,
        [
          'single'       => true,
          'type'         => 'boolean',
          'default'      => false,
          'show_in_rest' => [
            'schema' => [
              'type'    => 'boolean',
              'default' => false,
            ]
          ],
        ] );

and I am using it in a custom sidebar panel:

import { ToggleControl } from '@wordpress/components';
import { useEntityProp } from '@wordpress/core-data';
import { useSelect } from '@wordpress/data';
import { PluginDocumentSettingPanel } from '@wordpress/edit-post';

const CustomPanel = () => {
  const postType = useSelect((select) => select('core/editor').getCurrentPostType(), []);
  const [meta, setMeta] = useEntityProp('postType', postType, 'meta') || {};
  const {
    custom_field
  } = meta;
  console.log(meta);

  return (
    <PluginDocumentSettingPanel
      name="custom-panel"
      title="custom panel"
      className="custom-panel"
    >
      <ToggleControl
        label="Toggle"
        onChange={(val) => setMeta({ ...meta, custom_field: val })}
        checked={custom_field}
      />
    </PluginDocumentSettingPanel>
  );
};

export default CustomPanel;

The console.log always outputs {custom_field: null} even though I set a default value in register_post_meta

The toggle does work, and sets the value as expected, however the first time I use it, it throws a warning

Warning: A component is changing an uncontrolled input to be controlled. This is likely caused by the value changing from undefined to a defined value, which should not happen. Decide between using a controlled or uncontrolled input element for the lifetime of the component. More info: https://reactjs.org/link/controlled-components

It seems the default value doesn't get passed to useEntityProp?
So I have to resort to doing

      <ToggleControl
        label="Toggle"
        onChange={(val) => setMeta({ ...meta, custom_field: val })}
        checked={!!meta?.custom_field}
      />

Am I doing something wrong or is it a bug?