Hello everyone!

So I am having my laptop repaired and I am currently streaming my videos on my newly bought Lenovo Yoga 2 Tablet which has Win 8.1 installed.

I have had huge performance issues, but on some very rare days everything works fine. Here is my problem:

When watching videos on youtube everything is perfectly fine and videos are being streamed in highest quality with no problems, probably due to the very good Internet I have here. (Speedtest confirmed about 45 mbps)
As soon as I try to watch bigger videos on sites like vidzi, I am getting no where. Even when I pause the video and let it load it doesn't get anywhere. (As I mentioned before on some very rare days everything works kinda fine, still not as good as expected but I can still watch the videos)

Things I have tried to fix this/problems that I ruled out:
1. The router is right behind me, true there is a wall between us, but that shouldn't be a problem I have full bars.
2. Browser: I have tried Chrome, Firefox, Opera, no difference.
3. I have closed every application except for the browser and the video site to see if it was an issue of space, no difference.
3. Flash Player: I have disabled the hardware accelaration, no difference. (I also increased the local storage but I am not sure if that has anything to do with it)
4. Clearing the cache/history/thingy on every browser, no difference.
5. Restarting the tablet, no difference.

Things that I am not sure about if they could be the issue:
1. Does the Lenova Yoga 2 Tablet just have awfull wifi reception?
2. Can I be limited by my provider if I stream too much? (but shouldn't that also change my speedtest.net results?)
3. Can Adblock Plus interfere with the loading speed?

Basically I have no idea and there might just not be a solution, but if you guys have any idea, I am willing to try it!!!