can't play online in my home network

Sorry if this question doesn't belong here, I bought a new 2ds XL a couple of days ago and I can connect to the wifi just fine and browse and update my DS the day I bought it, but when I tried to play a game I can't access to any online feature, I tried Yokai Watch 2 and Pokemon Ultra sun, they work when I use my phone hotspot so it's not a 2ds problem per se, I think it's my router blocking the way to nintendo servers, I checked their support site but it didn't work

I haven't found a solution so far

the error code I get in yokai watch 2 is Error code: 018-0201