Brand new to home Internet and hoping to improve speed

If you get the PCI value you can search for it on CellMapper.net and locate the tower that serves that signal out. With a 4G LTE / 5G NR capable phone it should be possible to obtain the cellular metrics for both signals. The bars on the LED screen are rather generic and do not provide enough information. It does not sound like you are receiving a 5G signal with those speeds or it is a very poor signal reception. 

You state you are using CellMapper on your phone so are you looking at 4G or 5G signaling or both?

With CellMapper.net in a browser you can provide your area code to get the general location and then display 4G LTE, 5G NR, or both. I find filtering for one or the other helpful. You will see more 4G LTE towers and IF the 5G cell you receive is on the map that really helps but CellMapper is not 100% as it does rely upon users using the Android application and uploading the findings to the server to have the data installed into the database. This does require an account but it does not cost anything to set up. CellMapper seems to be one of the best resources for locating the cells still. Below is a chart that will help you determine more about your cellular signals. Use the T-Mobile home internet mobile application on your phone to see the cellular metrics. Determine if you really are receiving a functional 5G signal.