After some messing around with support my site loads with this CDN. Support had to change something called CORS since no CSS was parsing when I loaded my site. But now it seems I'm having a login problem and it might be cookie related.
Question: Are phpBB cookies tied to an IP address somehow? This might be an issue since I have an origin and CDN IP. Though, I never had this issue with CloudFlare. I thought it might be the cookie domain, so I temp changed it to .stackpathcdn.com in one browser and then launched another browser to try and login through the CDN but that didn't fix the issue.