When downloading games browsing is very slow

Hi guys when im downloading games on Steam or updating the system my Browser gets very very slow even sometimes not loading websites at all.

I never have that beaviour with Windows on the same system which is weird.

Im using a wifi dongle, cant run cable at my place, and like i said on Wibdows i would just press Download and watch youtube videos in the meantime but here i cant even get to google.

Is this a Linux thing im not avere of that o need to tinker? or what?