Access-Control-Allow-Origin

I'm getting an error sometimes when accessing the item_breakdown endpoint. It'll work fine the first few times and then I'll get his error. I'm masking out specific information in the calls and responses to paste them here.

The endpoint:
Request URL: https://backstage.taboola.com/backstage/api/1.0/##########-altium-sc1/reports/top-campaign-content/dimensions/item_breakdown?start_date=1900-01-01&end_date=2020-02-17&campaign=##########
Referrer Policy: no-referrer-when-downgrade

The response message after the call errors out is:
accept-ranges: bytes
content-length: 0
date: Mon, 17 Feb 2020 21:27:02 GMT
server: nginx
status: 429
via: 1.1 varnish
x-cache: MISS
x-cache-hits: 0
x-served-by: cache-chi21133-CHI
x-timer: S1581974823.691708,VS0,VE160

The error in the browser console is:
Access to XMLHttpRequest at 'https://backstage.taboola.com/backstage/api/1.0/###########-altium-sc1/reports/top-campaign-content/dimensions/item_breakdown?start_date=1900-01-01&end_date=2020-02-17&campaign=###########' from origin 'https://###############.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.