## Bug description

If I mark an insight as a favorite (⭐) and then refresh, the insight is no longer marked as a favorite although it is (can see it in Favorites).

<img width="390" alt="image" src="https://user-images.githubusercontent.com/30181361/182802236-9ecf0531-899c-4f25-ae86-bc233cefdc2f.png">

Note that I'm in the _Favorites_ tab and that _Bug example_ is not starred.
## Environment

- [x] PostHog Cloud
- [ ] self-hosted PostHog, version/commit: please provide

posthog/api/test/test_insight.py
dashboard_id, _ = self._create_dashboard({})
        insight_id, _ = self._create_insight(
            {
                "filters": {
                    "events": [{"id": "$pageview"}],
                    "properties": [{"key": "$browser", "value": "Mac OS X"}],
                    "date_from": "-90d",
                },
                "dashboards": [dashboard_id],
            }
        )
        tile: DashboardTile = DashboardTile.objects.get(dashboard__id=dashboard_id, insight__id=insight_id)
        self.assertIsNotNone(tile.filters_hash)
    def test_adding_insight_to_a_dashboard_sets_filters_hash(self) -> None: