The tower my phone normally connects to has a strong signal but capacity is very congested and speeds are very weak. So I tried out the LTE cellspot and noticed that 90% of the time my phone stays connected to band 66 on the tower and disconnects from band 4 cellspot frequently. Checking the signal strength I find the cellspot a little better in strength but speeds are quite horrible. This result is based on no other devices connected to Wi-Fi at the time so there should be no drain on my ISP connection and it's very doubtful there's more than one or two other T-Mobile customers who are within range of the cellspot.
I can see the phone automatically connecting to the stronger signal or the better signal in relation to capacity and speed. However I don't understand why a near-perfect cellspot signal with plenty of capacity can be overridden by a tower with weaker signal and a lot more users in relation to capacity.
Is this a band 4 vs band 66 issue?