Hardware iMac completely knocks out Switch Lite (but not Switch) Wi-Fi?

[NekoMichi]

EDIT: It was the USB hub, not the iMac. The reason is still unexplained though. See the updated note for details.

Original post:
So a really weird problem started happening today, not sure if anyone else has encountered this or knows how to fix it?

I'm currently using a 2017 iMac and normally play on my Switch Lite at my desk in front of it with no problem. Today my Switch Lite suddenly stopped connecting to the Internet and couldn't detect any Wi-Fi networks. After moving around I noticed that this only happens when it is positioned within 50cm of my iMac, and if I power the iMac off then the Switch Lite will connect to Wi-Fi perfectly fine no matter where it is in the room. While this might sound like wireless interference, the strangest thing is that my iMac is connected entirely by Ethernet; Wi-Fi and Bluetooth are both disabled on the machine yet simply by having it powered on it will completely knock out the Wi-Fi on my Switch Lite. This never happened before and has only just started happening today.

Even weirder is that if I repeat this test with an OG 2017 Switch the problem doesn't happen at all, and neither does my phone or tablet suffer the same issue when near my iMac. It's just my Switch Lite that's no longer able to use Wi-Fi when nearby.

Does anyone know what exactly could be the cause of this? It's not wireless interference and it only just started happening today.

UPDATE: It might be caused by a USB hub, somehow?

After unplugging all of my peripherals and reconnecting them one by one, I was able to identify that the issue was caused by a USB hub, one that looks like this:

The Switch Lite is able to connect to the Internet when this hub is removed but the connection fails as soon as I plug this hub back in. I was able to reproduce this issue by plugging the same hub into a Windows machine and it knocked out my Switch Lite's Wi-Fi immediately. But this still leaves a few unanswered questions:

- How does a wired USB hub completely knock out Wi-Fi like that? The hub doesn't have any Wi-Fi capabilities on its own, it has a micro USB 3.0 port on the back and a cable that connects to USB A 3.0 on the other end.

- How come this only affects my Switch Lite? During my testing, an OG Switch, a smartphone, and a tablet all connected to Wi-Fi just fine no matter if this hub is connected or not. It's just the Switch Lite that doesn't like it.

- This only started happening today and my Switch Lite never had these Wi-Fi issues in the past even with the USB hub connected and in the exact same physical location. What could have changed to suddenly cause this issue?

- Changing Wi-Fi channels didn't fix it.

- For compatibility reasons, usually my network is 2.4GHz (channel 11) only. Just for testing, I enabled the 5GHz network and tried to connect to it on my Switch Lite while the USB hub is plugged in. As soon as the "connecting to the Internet..." popup displayed the entire Switch OS froze on me. It didn't crash or display any kind of error message, the bouncing dot between the console and network device icons was frozen mid-animation and none of my button presses worked. I had to hold down the power button and force-reboot the console.

- This isn't even the first time I've had a wired device completely break wireless connections before, although my previous experience was under different circumstances.