Slow 4G connection only, but only sometimes -- SOLVED

Hello, I wanted to reply here to bump this post up and say thanks to the community for helping me fix my issue. I didn't get into the depth of signal and tower mapping that others did here, but a specific part of the OP's comments here stood out to me, and I thought might be helpful to others struggling with their connectivity/signal strength issues as well.

TL/DR from the OP:
"Although it is counterintuitive, because usually higher bars means better connections and faster speeds, but it turns out sometimes not. By simply placing the gateway a few feet from the window, to a place where it gets only 2 bars instead of 3, I was able to connect right away to my fastest speed and remain there for the rest of the day.”

More on my specific experience, if you are interested...

I have been wrestling with spotty connectivity since I got the service a couple weeks ago, and experiencing similar problems as others are (overwhelmingly) reporting here. Super intermittent speeds, frequent drop-outs, needing to reset the gateway multiple times a day. For the most part it was working well enough, and even with the disruptions slightly preferable to the 40mbps DSL I was moving away from, but...really not ideal. So I spent 2 worthless hours on the phone with T-Mobile support, and a lot of time here combing through threads, considering buying a fan, asking for a new gateway, etc. 

Ultimately, the most important thing to me was the reliability of the signal to my main home PC, which acts as a media center for the house. We have lots of other devices that were working pretty well (Sonos, Fire TVs, phones/laptops, etc.) but the Windows 10 PC is down in the basement, and I could not get a dependable connection there even after buying a new PCI wifi card (TP-Link AC1200, fwiw). I was messing with the gateway settings, frequency bands, etc. and nothing really worked. I could sit at that desk with my laptop and pull 100+ mpbs while the PC was struggling to maintain single digits. Not great!

After reading this thread, I decided to revisit the very first assumption I made when setting up the gateway. It should be on an upper floor, by a window, to get the strongest signal, right? The best placement upstairs got me 3 bars, and seemed intuitively better than putting it in the basement, where I could only get 2 bars. But I found a location by a basement window (just 10 feet below my original placement), where even though I am only getting 2 bars, it DRASTICALLY improved my connectivity and signal strength to the PC and everywhere else. A little trade-off for a couple of the Fire TVs that it is now further away from, but still getting durable 40-80mbps for those, so no noticeable loss in streaming performance. I think moving it resulted in a change in the primary band I was connecting to (from 12 to 2) and this seemed to make the difference. 

So that’s my story, and my recommendation. Even though you might sacrifice a bar, do not be afraid to get creative with your placement, and see if you get better results with 2 bars then with 3. This really seemed to solve the issue for me, and will likely make the difference with me keeping the service rather than going back to DSL.

Best of luck to everyone...this was pretty frustrating and while I typically appreciate T-Mobile's customer service, they are apparently pretty terrible on the home internet front. So while we are left to our own devices I'm glad there are helpful people like you all out there! :)