Why does my stream continue when internet briefly drops out?

[royarcher]

When I am streaming something using,say express VPN,s DNS servers at times my internet may drop out going by the little light on top of my RT AC 88 U,eg going from white to red but I am still able to stream for quite a while before it stops. How is this happening? I would have thought that once the red light goes on the internet traffic should stop as it does on my laptop and phone but it doesn't stop on my Roku device

 

[ColinTaylor]

Because your client is buffering a lot of data ahead of time. It could also be that your internet hasn't "dropped" at all, but you're experiencing a brief DNS issue.

 

[toaruScar]

I don't see why you mentioned DNS here, but a bad DNS does not affect TCP nor UDP connections. It only plays a role when to try to resolve a domain name.
Or maybe the light on your router is a false negative.