tmobile home internet speeds are great but all of my video games lag?

If you don't mind post some detail about your connection.

Phone app is a bit limited go to 192.168.12.1 on your computer web browser.

First page expand Primary and secondary internet connection signal all that info is needed screen shot ok too.

Then on the left click Status and again expand Primary and secondary cellular network again all that data or screenshot.

Again need 

RSRP

SNR

RSRQ

RSSI

For both primary and secondary.

And Band for both.

I know your speed is good but lets see how good your signal is.