Second Monitor Framerate/Stability Help

[NoirCore]

I've come to ask help from the tech brains of around here.

So I've recently bought a USB-to-HDMI cable as a means of setting up a second monitor, that being a TV. Said TV would act as my extended screen for stuff. After some setup, it works...sorta.

The screen indeed shows up, but the framerate is not perfect on the TV screen (though the computer's screen still runs smoothly). I've noticed this while watching Twitch on my TV screen in that even on 60fps quality, the picture does not reflect the framerate, and not just the Twitch video; this extends to the WHOLE screen, like my mouse movements. In fact, should it be connected to a hub, it's on screen (with the low framerate) for a good while before it disconnects and also makes the hub "disconnect" and "reconnect" until I unplug the second screen cord.

My aim is to get my second monitor to show video from my computer at 60fps and stay that way. Here's what I got:

-My computer is a Microsoft Surface Pro, I think a 3.

-I used two different HDMI cords. Both pretty much had the same effect.

-I used two different TVs, including the one I usually watch stuff on. Both TVs show other stuff at 60fps properly, but still had the lower framerate with the extended screen from the computer. I used both cords.

-I tried connecting the cord to the hub connected to the computer and then to the computer itself without the hub. Both had the lower framerate. I haven't bothered waiting to see if the picture when the cord is connected to the computer and not the hub goes out though.

-All times I tested this, Twitch was on my second screen.

So, with all that information, I hope someone here can give some help as to what I should do. I've searched on Google, but I couldn't come up with a proper answer. Do I need a new computer? Do I need to add something to my setup? I beg thee for your help.