## 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/insight.py
if should_refresh(self.context["request"]):
            return insight.team.timezone
        result = get_safe_cache(insight.filters_hash)
        if not result or result.get("task_id", None):
            return None
        return result.get("timezone")
    def get_last_refresh(self, insight: Insight):
        if should_refresh(self.context["request"]):
            return now()
        dashboard_tile = self.dashboard_tile_from_context(insight, self.context.get("dashboard", None))
        result = self.get_result(insight)
        if result is not None:
            if dashboard_tile:
                return dashboard_tile.last_refresh
            else:
                return insight.last_refresh
        if dashboard_tile is not None:
            if dashboard_tile.last_refresh is not None:
                dashboard_tile.last_refresh = None
                dashboard_tile.save(update_fields=["last_refresh"])
        else:
            if insight.last_refresh is not None:
                
                insight.last_refresh = None
                insight.save(update_fields=["last_refresh"])
        return None
    def get_effective_privilege_level(self, insight: Insight) -> Dashboard.PrivilegeLevel: