Unable to communicate with other console

[loveclove]

What is this error?
I have been getting it with a few specific people. Today I had someone trying to come over and the error showed for them, then I tried to come to their island and it showed to me. So I had someone else come over to test the dodo and it worked like a breeze.
Last week I tried to go to a giveaway 3 times with 3 different codes over the course of 2 days and the error always showed, but I continued to visit other people and have people over normally in the meantime, so I'm assuming it's not the internet... What's the issue?

 

[Rosch]

I've encountered it once. I had to reset my modem. It does seem that you have a good connection when it's actually not.

 

[loveclove]

I've encountered it once. I had to reset my modem. It does seem that you have a good connection when it's actually not.

How do I know it's my connection and not the person's? And why it works normally with some islands and decides not to work with others? Just curious

 

[Rosch]

Honestly, I don't know either. When I have connection problems, my first step of troubleshooting is to always reset the modem, regardless if I have the bad connection or not.