Cannot Access Some Websites When VPN Is Enabled

Hello,

My PC is Windows 10 Pro v21H2, 64-bit. I use Firefox v99.0 as my browser. Why can I not access some websites when VPN is enabled? The most recent example is www.longhornsteakhouse.com. If I disable the VPN, I have no problem accessing the site.

Why does this happen and is there a solution to fix it?

Thanks!