Technical issues regarding Nintendo 3DS?

Apologies if it was already posted, but it's rather frustrating.
The issue is this: When I try to open the home menu, the system freezes and doesn't respond.

Sometimes it just get stuck in the black screen when I return home with the system turned on.
I have discovered that the system works if the wifi is turned off, but it take away the whole joy of playing games.

The problem only happens at home, while internet works just fine in my work place or when I'm doing online play at the bus station.

When I try to open the Station while I'm plaing at home, then the system will freeze when Porter asks if I want to invite/visit friends local or through internet.

I also noticed the system freeze when I try to close the ticket gate.

Unfortunatelly, the issue doesn't just happen with New Leaf, but the other 3DS features like miiverse, camera and other things.

From what I noticed it happens with my two 3DS, not just one.

It's not a coincidence since my nephew's 3DS ended up having the same issue after I configured my internet on it.

I believe that my young brother is behind the unstable internet at home, however he refuse to admit it.

Worse is that it started when he took my other modem without permission to install internet in his bedroom.
It started to occur even after he stopped using my other modem which is so frustrating.

So your 3DS crashes and freezes when you play at home with WiFi on. It works fine in other WiFi hotspots like cafes and such. It also works fine if you turn off WiFi at home.

When it works well in other WiFi hotspots, there's no interruption at all? Same when you're at home with WiFi off? Everything is smooth.

The confusing thing to me, is I used to live in a dorm where I could not jump pass the firewall, and I had no WiFi at all. The internet blue icon would switch to the streetpass green icon. I tried to connect to the internet to get DLCs and I only got an error then the game still continued.

But yours crashes. When it freezes, does it ever fix itself? This isn't like bad lag. This more like you're forced to press the power button and turn it on again? I almost want to say it's an internal problem with your 3DS. Like it's your WiFi switch hardware itself or something.

That's really perplexing.

Yeah, I would say it could be internal issues as well since it's freezing a lot when you play. I had an old 3ds xl that made those freezing things literally every time I tried to make progress in games. My internet is usually chill though so I'd guess it could be that one messing up.

I'd try sending it in to Nintendo though if they still run those error reports and if they can help you with it. And try talking to your brother and/or parents about it, if you can. I feel you when I can't get on, it indeed takes away a lot of fun when a lot of games are built around it, too.