The same thing happens to me, I have 100 Mbps fiber and I only have problems with the official Ark servers, I am having to use a vpn, I suppose that if I change my public IP the problem will be fixed, but the process to change the ip in my provider takes a long time, wildcard should do something with this
I need to mention that the solution that the one who created the post put did not work, it only worked for me to use a VPN or another internet network.