^
Trying to figure out what you meant by EarDemon. I click on that and Chick - Fila comes up. But anyhoo, still Leary about speed checks. My results are all over the place and I have no issues with my speeds.
My handle on this site is EarDemon, my avatar is Chick-fil-a logo. Not sure why you're not seeing that but doesn't really matter I guess.
Anywho, I guess if it doesn't bother you that you are not getting consistent speeds, that's your prerogative. Me personally, because this is my thing, I would go to the ends of the earth and be making phone calls, have techs come out and the whole nine yards. Not knocking you by any means. I'm supposed to get 20 highway miles to the gallon in my truck, I've never the on-board diagnostics report anything above 17.5 and I don't care. Some people care about fuel economy, I don't. Some people would go to great lengths to improve it, I won't. As absurd as that may sound to some people, not getting a consistent 900 Mbps sounds absurd to me, but if it doesn't bother you or it's not a concern that's fine.
Three or four years ago when I was on Time Warner's 50 x 5 plan, at one point I could max out at 30 - 35 down, I was on the phone within in a few days with my regional manager contact telling him that is unacceptable, especially considering the overprovision to 60 Mbps, I lost half of my speed. During the time I discovered the problem and the time I called him about it and when though a bunch of testing on my end. Turns out while not a direct congestion problem, I live in the middle of nowhere and node utilization reports were coming back with 60 - 70% utilization during prime time, I was on an an older CMTS that was having problems with traffic. I can't remember now if it was the Arris C4, or if I was ungraded to the C4, but once the swap was made I was back where I was supposed to be
While there are some varying options, speedtests should give you a pretty good ball park figure where your speeds are at.
This is the information from Ookla on how speed tests work
How does the test itself work? How is the result calculated?
Now your impossible results are not unheard of. Years ago I would get pings of 0 on occasion which is impossible. And on the Windows 10 Ookla app, my upload speed constantly comes back at 60+, which is also impossible since I know for a fact it's provisioned at around 42.5 Mbps. Somewhere I have the direct link to the file that is used to test the speed on the meters that Charter techs use, and I would always get 115 MB to 117 MBps (920 Mbps+) downstream.