I have switched our CDN provider and inputted the new URL in the settings page accordingly. Most of the site is working fine, except for background images (theme files) in the CSS which is referencing the old CDN URL. I have cleared every cache known to man, manually deleted the generated files, uninstalled CDN & reinstalled, scanned the database for the old URL... nothing!
I can't figure out where this old URL is coming from. Any ideas what else I can try?