Hardware HELP: Can't connect to the other console in Smash Ultimate

[Yober]

ERROR CODE: 2618-0513
we're both NAT type B and living in the same city, I enabled DMZ on my router but might've not done it correctly because I can't really find any in depth tutorials of doing so

 

[Draxzelex]

ERROR CODE: 2618-0513
we're both NAT type B and living in the same city, I enabled DMZ on my router but might've not done it correctly because I can't really find any in depth tutorials of doing so

Your Internet speed is not good enough for peer to peer connections.