Reformatted for mobile users:

Had the same problem with Raspi 4B. Problem was dependent on screen resolution (!!). With 1920x1080, wlan0 became disconnected after it was ok at lower screen resolutions. Was in 2.4GHz band. After turning on 5GHz in the router and going into the network preferences (right click the network icon top right on screen) and SSID ... and checking "automatically configure options" the connection remains stable (so far :D ).

This is a good reminder that every digital circuit is really a fancy analog circuit. Your program may be perfectly correct, but when it runs on faulty hardware, you are hosed no matter how many times you’ve formally proven it.

or even a perfectly functional hardware in presence of EM noise.

Reminds me of the MacBook Air that I have (2018 model).

When I connect my USB 3 hub to it, I lose my WiFi :(

I Googled it when it happened a while back, and apparently other people have this problem with the MacBook Air too.

Some choose to shield the USB 3 cable with tinfoil. Personally I opted to connect a USB 3 Ethernet interface to the hub and use wired Ethernet when I use the hub.

In the very distant past (late 1980s, early 90s), Olivetti changed their PC keyboard design; it went from having the keyboard PCB assembly inside a metal clamshell to a bare board with a metallised plastic sheet on the back of the PCB (they 'cheaped out').

We got to know about the design change when a rather large and sprawling local leisure centre reported that often when someone used their walkie talkie near a PC, the screen filled with random characters and sometimes the dot matrix printers would 'go haywire' (CTRL-P = Print what's displayed on the screen).

In effect, the rf signal from the walkie talkies was 'mashing the keys'.

The immediate fix was to swap in some older keyboards, the longer fix was down to Olivetti using better shielding and some appropriately-placed capacitor decoupling on the power and signal lines.

> "In the very distant past (late 1980s, early 90s), Olivetti..."

Havnm't heard that brand in a while! I now remember I still have an 486 DX4 100MHz Olivetti laptop. Which is kind of pink-red-brownish.

First time I saw a room full of non-crt computer monitors, found out Merrill Lynch moved to a new building to save money. What they discovered is the CRTs would weird out every time the subway train went by. All the cash saved by moving was lost buying the stupid expensive monitors.

I wouldn't have considered trains to be a source of EM interference but in retrospect it makes sense. one that's amazed me is that military jets and warships cause some of the nearby consumer electronics go wonky, but as they literally run systems that are trying to jam radio waves, it makes a ton of sense that eg garage doors have trouble keeping up.

Is it possible the walkie talkie was out of spec as well? Little signal booster added after market?

Doesn't have to be. If I TX with 5W near my new Lattitude laptop, the cursor goes all over the place. I've heard of electricians using uhf radios tripping GFI breakers. I guess what is normal power levels in ham / professional radios are much more than most other stuff is designed to withstand.

Here you are: https://www.intel.com/content/www/us/en/products/docs/io/uni...

it happens with macbook pro 2018 as well. but only with adapters from amazon, using official adapter from apple store seems not to have that problem.

wrapping 3rd party adapter in tin foil actually show much better speedtest results when connected, then without the foil.

Brings back fond memories of an extremely laggy Logitech wireless mouse whenever an external display is plugged into the MiniDP port on the same side.

Fond memories of wondering why WiFi occassionally stopped working - eventually correlated it with the use of the microwave.

Cheap hubs or cables have been causing this since 2016

2016? It's been happening since before electronics existed to allow the personal computer to be invented!

Similar problem with my 2014 MBP: I lose wifi if I plug it into my UHD monitor with a DisplayPort cable, but not if I use HDMI. Probably has to do with cable quality (bought it on Amazon).

I have that issue with my 2016 MacBoo Pro, but I'm pretty sure it's due to my crap quality USB3+NIC that I bought.

I had this problem until I threw out my $10 USB 3 hub and got a $20 one instead.

I have a thunderbolt to 4 port usb 3 hub that when connected to a 2019 MacBook Pro interferes with the mouse pointer (it sticks and the pointer goes large every few seconds). Could this be related?

That could be an electrical grounding problem. In my experience touchpads are very sensitive to the quality of the power supply.

Yeah, we have crap power where I work and have cut down a lot of weird, random issues by buying a decent UPS for each worker machine. Even the people with laptops.

5GHz wifi is a lot more stable. Mine used to disconnect with microwave running. Also your hub might have leaky cables. I had an issue like this with bad hdmi cables too.

Microwave ovens and wifi use the same frequency range for the same reason: 2.4 GHz is available as unlicensed spectrum. In theory someone could build a 5 GHz microwave oven, but it wouldn't be cost-effective for a consumer appliance.

I once heard something about that frequency working better with water molecules, but after looking it up I think it's a myth.

A 5 GHz microwave would be more efficient but you don't necessarily want more efficient for cooking - that would just heat the outside of the food fastest. Commercial microwaves apparently run somewhere in the 900 MHz band. There are some neat graphs here:

http://www1.lsbu.ac.uk/water/microwave_water.html

What kind of cables are you using? Either your cable or hub isn’t up so spec and properly shielded.

Why not simply buy a shielded USB cable?

I have this problem with the macbook pro

Yes, although Eben Upton suggests trying a better grade of HDMI cable... the frequency of the higher resolution on screen will radiate noise out of a poorly shielded cable enough to interfere with Wi-Fi in the 2.4Ghz range.

Don't use a cheap cable, use one rated for 4k, and see if that helps.

Likely, but I've also had strange effects like this that have ultimately been traced back power domain issues on some of our devices.