home internet .

Use the mobile application and verify the cellular metrics. If the signal is strong but low quality and there is a significant amount of noise that will result in poor performance. The time of day/night is going to be a factor to contend with due to user load. Another set of factors are the frequencies received. Does the gateway have both the secondary and primary signals? Make sure the gateway not only receives the 4G LTE primary channel but is also receiving the 5G secondary channel. If you have an Android phone load up a Network Analyzer that also provides info on the cellular signals it receives. Compare the information with the metrics for the gateway. If you have an iPhone put it into Field Test Mode by dialing *3001#12345#* and look at the cellular metrics and identify the cellular frequencies received. If the phone has a hard time with reception the gateway will probably suffer as well.

You might need to check with T-Mobile and see if they are doing work in the cells in the area. If they are doing upgrades expect disruptions and unpredictable service for at least a week. They tend to do maintenance and upgrades during the day so one never knows what is going on. When the service is all over the place for speed and unpredictable I have seen it often is related to upgrade activity. So, confirming service status for the area is a good idea to help keep your hair.