413 Entity Too Large on GET /api/v2/analytics/conversations/details/query

I’m completely stumped as to why the Analytics API returns 413 Entity Too Large for a 90-day date range.

1. POST /api/v2/analytics/conversations/details/query with from 90 days ago.
2. Receive 413 status.
3. Reduce range to 30 days → 200 OK.

Splitting the query into three 30-day chunks works, but the payload size seems within limits. Is there a hard limit on the dateFrom/dateTo span or result set size for this endpoint? How should I structure the loop to avoid hitting this?