Struggling with API truncation limit

Hi community, I am banging my head against the wall in regards to the host list detection API call I am using, trying to get a list of all vulnerabilities with no truncation limit. I have set truncation_limit=0 in my API url but I receive an error each time I apply in Power BI. I can't figure out why the 409 error is occurring, I am only making one API call. Any help would be greatly appreciated! Thank you.