I tried turning on Compatible Mode for Resource Files and copying the icons from admin, but that didn't change anything. Maybe I have something wrong in my KeyCDN setup? I've cleared joomla cache and purged keycdn data.
Of course you were correct and it was an issue with the Regular Labs CDN for Joomla extension. The dev updated the extension and now the images are appearing on the map. Have a great day. I will send a donation.