I've had this issue as well for well over a year.
Despite how much everyone tells you you should use a VPN, lots of sites REALLY don't like it when you do, including Fakku from the looks of it. I imagine this is something that can't really be fixed on their end, seems to be in the hands of their server host. I also have Nord, and for the longest time, using the dedicated IP specialty server seemed to be the key to bypassing the issue. Within the last week or so, that no longer seems to be the case.
So if you want your anime pr0n, looks like you're gonna have to go raw.