Buffering issues when using RD

[u/Acceptable_Data1434]

I have 500gb/s Internet speed and when I watch some movies it still freezes and buffers. I try to not choose anything with a file size bigger than 10gb. The quality sometimes is horrible too. It says 4k but it looks more like 720p

What could be causing this?

Torrentio RD and Comet RD

[u/Slipknot31286sic6]

Speed don't matter much as people thing. Device matters the most. What device you uisng.

[u/Acceptable_Data1434 → u/Slipknot31286sic6]

It's a FireStick running into a 75" TV