I made this account a year ago i think and I just got back into AC i normally used to use ACC but its soo dead so I came here..
i just wanted to say Hi im kinda a noob since I have barely been on this site.
But hello! :)
Go to the nintendo support chat and tell them what happened let them access your router settings and they do something there which allows your 3ds or something to access the wifi properly or something like that
it works