Ok, keep us posted. I've added this to the bug list.
D-Link called back earlier today. As I was not home at the time, they gave me instructions to try. This consisted of re-doing all the settings I already went over multiple times, and trying to set a static IP address. Which, to me, doesn't make sense as the router gives local IPv6 Addresses, just won't let IPv6 connectivity go through. But, still, no success. For now I've unplugged the router and replaced it with my older TP-Link 1043ND.