How do I use the platform filter in campaign summary report?

Hi,

I'm trying to filter our campaign summary report by platform, but right now it doesn't seem like it's working - platform=DESK, platform=PHON, and platform= TBLT all return the same results.

Here's a sample query

https://backstage.taboola.com/backstage/api/1.0/{our_account_id}/reports/campaign-summary/dimensions/campaign_site_day_breakdown?start_date=2022-11-02&end_date=2022-11-02&platform=PHON

What am I doing wrong here?

Thanks,
John