You can call your internet service provider and complain if your speed drops under what they have promised. I've had a similar problem when I switched to another isp, my internet speed would variate between 210Mbps to 2Mbps downstream, and in my case the router was defect. So try a speed testing software or website, like speedtest.net or even better if you have a more local site for your country since i've experienced speedtest.net to vary a bit in the results even if you choose a server nearby.
When I complained to my isp they could see that the router was acting up and sent me a new one, and now my internet speed is pretty stable.
When I complained to my isp they could see that the router was acting up and sent me a new one, and now my internet speed is pretty stable.
