Engagements only listing one contact center 'flow' in API results

In json results, engagements that start in one flow and ‘route to’ another flow only display the initial flow in the ‘flows’ result.

In short, when querying GET /contact_center/analytics/historical/details/metrics?channel_types=voice, I expect to get multiple flows for engagements that are routed to multiple flows. What determines whether a flow is logged in the database?

For example, I have engagements starting in a flow ‘TEST Flow’ and then routed to an ‘Outage IVR Flow.’ I expect both flows to be in the flows result, but only the first TEST Flow is present.