Severe slowdowns and lag after 2am CT

@sdscott, many users who experience your symptoms (fluctuations in performance) return to the basics and find a resolution. Here are a few steps to double-check. For perspective, remember that the TM tower never moves, as with your gateway, so placement is important. 

Did you use the Placement Assistant in the T-Mobile Internet app? If not, you can access it from the TM Home Internet app (or T-Life app). Home Screen: tap the More about connection quality link on the Home Screen > Launch placement assistant > OK! Let's do this > You can watch the video if it will help, then "skip video," which will launch the placement assistant > enter your address or share location (if you use "share location" and your address shows up, then you are assured to be connected to the network). It will take 30-45 seconds to confirm your location.  Use the "Camera" mode for a direct visual of where your cell tower is located and where your gateway is located in your home. Ensure your gateway is located at a high point of your home and clear of any obstructions. Here is a helpful video: https://youtu.be/Q-DmRbQFuo0

What are your metrics - now that you are confident your gateway is located in the best possible location, your metrics will show the quality of your connection. In your T-Mobile Internet app > tap "MORE" at the bottom of the Home Screen > tap "Advanced cellular metrics" > tap "5G" > and let us know your RSRQ, RSRP, SINR, and which band you are connected to. You should be on band n41 or n71. Look at the chart posted below. To get the ideal readings, slightly rotate your gateway about 1/8th of a turn and then check the metrics to see if they change for the better. Repeat until you get the best metrics. 

My metrics are RSRP 74, RSRQ 19, SINR 40, and I generally get +/- 100 Mbps down and 30 Mbps up. 

Let us know what you find.