I'm stumped. New network, ICMP works but HTTP/HTTPS is spotty. Any ideas?

Here's the scenario. We have a new network we just stood up that connects back via VPN. I can ping and traceroute to any website without issue. For whatever reason though, only certain websites will work within the web browser. The goofy thing is I can connect to Twitter, Facebook, basically any Google service (YouTube, Gmail, etc.), but most other websites won't work. It's just this one site though. These things work fine at our other sites, and at corporate. Traffic flow essentially looks like this:

SonicWall NSA4500 -> Barracuda Web Filter -> Core VPN Router -> IPSEC to office

I've ran packet captures from the firewall and I'm not seeing any drops, everything is getting forwarded. Obvious suspect is the Barracuda, so we removed it out of the loop entirely and had the same results. Even when it's on the Barracuda shows the websites being allowed.

Ya'll, I'm entirely stumped. It just makes no sense. Anyone have any idea what may be causing this issue, or where I can look?

Thanks!

EDIT: Solved! Thank you all so much!