OK. I use Speed Test on the computer but for some reason questioned how accurate it would be for cell signals. I guess download/upload speed for internet activity is the same regardless of the device used.
Ookla seeks out the best server (as it determines) to run it's test against and I'm necessarily they are same as the server my phone on hotspot is using. I always note the location of the servers Ookla offers and then browse a website (like Harvest Hosts) to which I temporarily grant location privileges. Sometimes HH would resolve that I was in Chicago, Minneapolis, Denver, or Seattle when I was in the MT, WY, SD area the whole time. It kind of surprised me the first couple of times I had my laptop connected to my T-Mobile or VZ phone hotspot and browsed the HH map while I was in the Rapid City area only to get HH locations around Chicago or Minneapolis.