So I've got two VPN subscriptions, let's call them VPN A and VPN B. And I like going to a somewhat popular website, which I'll call Site C.
I'm a new customer to VPN B, and I've noticed that I can't access Site C while using VPN B. I can access most other sites with VPN B, but not Site C. While I'm using VPN A, I can access Site C. While I'm not using any VPN, I can access Site C as well.
So my question is: is there any reliable way I can tell whether VPN B is blocking Site C, or Site C is blocking VPN B, or both? I understand that there are certain ways I can make intelligent guesses, but I'm looking for something more like a "smoking gun".