Serious Problem: How reliable are VPN extensions like MullVad VPN for Firefox?

[win11.shading291]

I’m not sure if this topic would help?

Basic 101 Networking question

I always wondered this and should have asked way sooner about this, but here goes: when do app connect to the internet? Is there traffic going in and out at all times? Let’s take a specific example. If my steam app is opened and I switch from a vpn connection to the other, does steam sees this? Same question but for browsing experience. If I open 10 different tabs and they all already loaded. I turn off my VPN connection because let’s say a bank block all VPN connection. Will all the other tab…