Analytics API returning 404 for WhatsApp message volume metrics

Looking for advice on why the v2 analytics API returns a 404 Not Found error when querying message volume metrics for WhatsApp channels. The endpoint works for voice interactions but fails specifically for digital channels in the Europe/London region. We are using the standard reporting interval and have verified the date range. The legal team needs this data for a discovery request. Is there a known limitation with digital channel metrics in the current release?

Thanks for your help.