Nintendo Switch error code 2618-0516: why?

So, I have a Nintendo Switch. I bought Nintendo Online last October, directly for a WHOLE year. I then wanted to play Mario Kart online straight away, but I was shown the above error code and the following text: Can't connect to one or more consoles. I then tried my other games, including Smash. The same for every game if I wanted to play online.
I tried to find out why last year. I know myself that we only have a very, very weak line, a 2000 line.

As shown in the picture, I'm also given NAT Type C and many said last year that it was the NAT type. I don't know how to get it higher, I don't even know if that's because. BECAUSE: Fortnite works great.

I also came to play online levels at Mario Maker, but not online with other players. But only the uploaded levels.

as I said, Fortnite is running, which is why I'm a little surprised. Any game that comes from Nintendo does not work, but from Epic games works properly? Funny.

well, that's why I'm asking. Where does this error message come from?

please help me, I'm really fed up now.

ps: in August we will have a 50,000 line and if I can't do this I just have to wait 5 months. );

but well, I've been waiting for 5 months anyway, half would be done by then. );

Your IP is visible in the picture. (maybe you just shot the picture too…)

What exactly are you trying to tell me? Can't you show them? I'm not quite on the topic

Yes IP address is not good if everyone can see it.

Almost comparable to if you would post your home address.

But the picture has already been taken out.

Oh ok thanks Did you take the picture away?

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