## Bug description

When using the overall date filter on dashboards, after refreshing the dashboarditem will still show old data

## Expected behavior

Should show data that matches the overall filter

## How to reproduce

1. Add item to dashboard
2. Filter entire dashboard on date
3. refresh date

## Environment

- [ ] PostHog Cloud
- [ ] self-hosted PostHog, version/commit: _please provide_

## Additional context



#### *Thank you* for your bug report – we love squashing them!

posthog/api/test/test_dashboard.py
dashboard = Dashboard.objects.create(team=self.team, name="dashboard")
        filter_dict = {
            "events": [{"id": "$pageview"}],
            "properties": [{"key": "$browser", "value": "Mac OS X"}],
        }
        filter = Filter(data=filter_dict)
        item = DashboardItem.objects.create(dashboard=dashboard, filters=filter_dict, team=self.team,)
        DashboardItem.objects.create(
            dashboard=dashboard, filters=filter.to_dict(), team=self.team,
        )
        response = self.client.get("/api/dashboard/%s/" % dashboard.pk).json()
        self.assertEqual(response["items"][0]["result"], None)
        
        response = self.client.get(
            "/api/insight/trend/?events=%s&properties=%s"
            % (json.dumps(filter_dict["events"]), json.dumps(filter_dict["properties"]))
        )
        self.assertEqual(response.status_code, 200)
        item = DashboardItem.objects.get(pk=item.pk)
        self.assertAlmostEqual(item.last_refresh, now(), delta=timezone.timedelta(seconds=5))
        self.assertEqual(item.filters_hash, generate_cache_key("{}_{}".format(filter.toJSON(), self.team.pk)))
        with self.assertNumQueries(10):
            response = self.client.get("/api/dashboard/%s/" % dashboard.pk).json()
        self.assertAlmostEqual(Dashboard.objects.get().last_accessed_at, now(), delta=timezone.timedelta(seconds=5))
        self.assertEqual(response["items"][0]["result"][0]["count"], 0)
    def test_no_cache_available(self):