Mario kart 7 online doesn't work even though I already have a fixed IP address?

Mario Kart 7 online just doesn't work for me globally. I've been trying to play Mario Kart 7 online for 1 year. My internet is also very good. Now I've even reset my Nintendo, then once it worked globally, but then no longer. Then, as always, error code 006-0612 came up. Only community works. Then I also gave a fixed IP address but it still doesn't work. I really don't know what to do anymore. I even wrote to Nintendo, but they didn't answer me. But they will probably say that I should give an IP address, even though I already have one. Can anyone tell if he's okay and can someone give me a solution

Have you also released the required ports in the router (TCP 442 - 445 and 28000 - 29500 and UDP 1-65000)?

No how do you do that?

Which router do you have?

Fritz box

Do you mean that seriously? Which FritzBox?

Fritz! Box FonWLAN 7360

According to Nintendo, in addition to the static IP, a few ports have to be released:

TCP 442-445
TCP 28000-29500
UDP 1-65000

You have to proceed as follows with your Fritzbox:

Enter fritz.box in the browser and log in
Go to "Shares" in the "Internet" menu
"Port forwarding" tab
Add device for sharing
Enter the IP address manually: Enter the IP that you entered in your Nintendo
Then click on "New Share"
Select the entry "Other application" in the "Application" drop-down list
You can enter whatever name you want
Protocol: TCP
Port on device: 442
to port: 445
External port desired: Enter the same
Then you repeat that for TCP 28000 to 29500 and UDP 1-65000
Then activate release
OK

With me no port is requested externally

Oh, now I understand but what do you mean to repeat to me?

Besides, I don't get an UPD?

Ok i think i got it

With the upd when I want to release it comes to me that the port release can't be created or activated because a corresponding release already exists