I have 3 modems hg630 v2, zte h168n, and tp-link 9960 (the first 2 are isp supplied modems/routers) all the 3 modems report 28mbps for my line speed and 40mbps max attenable rate. the problem is when I download something or do a speed test I only get 20 Mbps and sometimes drops below 10 and the latency increases. I can fix it by restarting my modem but the issue appears again after a few minutes/hours. I called my isp but they said the cabinet from their side reports 28mbps and the line is stable without any issues thus they won't register any issues. the zte modem is the most affected as it also drops the upload speed by half no matter what the upload speed is.
at first, when I had the zte modem, my isp said it could be faulty, but then I bought the hg630 v2 and tp-link 9960 with the same problem, so I doubt it is a faulty modem. so does anyone have any idea what can cause this issue?
I currently live in Egypt and my ISP is telecom Egypt aka WE. I know most people here are from the UK but you are my last hope plus Kitz forum seems the most knowledgeable place for xDSL lines