Speedtest, browsers, and software. Results will vary.
I was getting concerned when i ran the speedtest on Cox.net using my chrome browser. I have utlimate service which is supposed to deliver 300 mbps. However, i was consistently getting readings of 60 - 70 mbps. I called tech support to troubleshoot and they are sending a tech out. However, i then checked the speed using the Microsoft Edge browser and low and behold the speed tested out at 330 mbps consistently. Went back to the Chrome browser and the reading was still below 100 mbps. I then used my chrome browser with Speedtest on the Ookla site and the reading was 300 plus mbps when not using the Cox server. If i use the Cox server closest to me, then the reading is back below 100 mbps when using Chrome browser.
My conclusion is that this is some type of software issue with the Chrome browser and the cox servers. Go figure. It is something that Cox should be aware of.