T-Mobile users might need to add a new APN:

Fill in the below info after the data is turned off:

Name: TAG
APN: fast.t-mobile.com
MMSC: http://mms.msg.eng.t-mobile.com/mms/wapenc
MCC: 310
MNC: 260
APN type: default,supl,mms
APN protocol: IPv4
Roaming protocol: IPv4

Once entered the info save this new APN and put a check mark on it, turn the data on and verify once again that the device has Internet connection on 4G/WiFi and that the filter is working.