Intense ping for no reason

[nastaliss]

Hello everyone !

Recently I've been having cases of really (I mean it) bad ping, reaching up to 400 ms on various games and pinging google.

I usually have around 20-50 ms .

I started investigating and unplugging ethernet cables one by one on the ethernet hub I'm plugged into, and I ended up finding that my brother's computer was causing this ping issue.
The thing is that it does that even when he isn't even using internet, but stops when he shuts down his PC.
He ran Malwarebytes as well as an antivirus but this did not change anything.
I'd like to add that this does not occur everytime his PC is on, but when it does it won't stop until shutdown.

Thanks in advance for your help

[TechFnatic]

Does he have the same problem when you're plugged into the hub? Hubs are layer 1 devices which means they're basically dumb switches, they broadcast all packets to every port. Basically what this means is if you have enough devices plugged into the hub collisions can occur and therefore mess around with how fast you recieve / send packets. Try plugging in directly to the router and see if the problem persists

[nastaliss]

UPDATE : we did a basic test : he closed one by one his apps on his desktop.
When he closed chrome, it went back to normal.
He then opened it again and the ping went high again.
So he disabled all his extensions and I believe the problem is now solved.
thanks TechFnatic for your help, even if the actual solution was way simpler than that