Home Internet Dreadfully Slow

Other than trying your gateway in various locations, especially a window in your house that is closest to the transmission tower, there's not much you can do. You can tell if the problem is something unique to the structure of your house by taking the gateway outside on an extension cord.

From what I have read, people who are getting less than 10 Mbps download on this have terrible problems with not only the slow speed, it not being the 50 to 100 they hoped for, but such a low  speed (anything under 10 or so) tends to fluctuate downward and make maintaining any usable connection impossible.

Your best case scenario is that in an unlucky coincidence, you happen to have received your gateway at a time they are doing some extensive work on your tower, in which case your gateway will seek out the next nearest tower, which might be 10 miles away. Thus you're getting a terrible signal. But this is something the support people should be able to determine, that your tower is being worked on.

For me, before getting the gateway, I knew 5G would probably work for me since my 4G Tmobile phone got between 15 and 50 on the download. I got the 5G gateway three months ago and now get an average of 150 download, with a recent peak speed of 276, and I'm 5 miles from the tower but that tower has the more desirable n41 signal/equipment.