Recently moved house and had installed my internet today, the exact same setup.
Right now the only difference with this setup is that the router is plugged into my laptop, and if anything, it's closer to my computer than it was in the previous house.
My problem is that it randomly goes slow for short periods of time, or in games it lags like crazy. For example while watching youtube it'll shoot up the loading bar fast and then all of a sudden stop, and go really slowly, then back into fast speed over and over.
What can I do to resolve this?