## Bug description

From [a customer report](https://posthoghelp.zendesk.com/agent/tickets/653):

```
I'm accessing insight results through the API, and I’ve noticed that sometimes the result is null in the response.
When I go and view the insight in Posthog and tap “refresh” the result starts to return in the API response.
I’ve also noticed there is a “refreshing” boolean flag in the insight response.
How do I set the insight to either refresh periodically or on request so I always get a result through the API?
```

It seems like the insight returns null if it's not refreshed manually from the frontend.

## How to reproduce

1. Call an insight with GET | /api/projects/:project_id/insights/:id
2. Response is `null`
3. Refresh the insight from the frontend
4. Response is populated

## Environment

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

## Additional context


posthog/api/insight.py
PATHS_INCLUDE_EVENT_TYPES,
    TRENDS_STICKINESS,
    FunnelVizType,
)
from posthog.decorators import cached_function
from posthog.helpers.multi_property_breakdown import protect_old_clients_from_multi_property_default
from posthog.models import DashboardTile, Filter, Insight, Team, User
from posthog.models.activity_logging.activity_log import Change, Detail, changes_between, load_activity, log_activity
from posthog.models.activity_logging.activity_page import activity_page_response
from posthog.models.dashboard import Dashboard
from posthog.models.filters import RetentionFilter
from posthog.models.filters.path_filter import PathFilter
from posthog.models.filters.stickiness_filter import StickinessFilter
from posthog.models.insight import InsightViewed, generate_insight_cache_key
from posthog.models.utils import UUIDT
from posthog.permissions import ProjectMembershipNecessaryPermissions, TeamMemberAccessPermission
from posthog.queries.funnels import ClickhouseFunnelTimeToConvert, ClickhouseFunnelTrends
from posthog.queries.funnels.utils import get_funnel_order_class
from posthog.queries.paths.paths import Paths
from posthog.queries.retention import Retention
from posthog.queries.stickiness import Stickiness
from posthog.queries.trends.trends import Trends
from posthog.queries.util import get_earliest_timestamp
from posthog.rate_limit import PassThroughClickHouseBurstRateThrottle, PassThroughClickHouseSustainedRateThrottle
from posthog.settings import SITE_URL
from posthog.settings.data_stores import CLICKHOUSE_CLUSTER
from posthog.tasks.update_cache import synchronously_update_insight_cache
from posthog.utils import DEFAULT_DATE_FROM_DAYS, get_safe_cache, relative_date_parse, should_refresh, str_to_bool
logger = structlog.get_logger(__name__)
def log_insight_activity(