I know I had been beaching about this before, after my OTA update, my LTE problem is gone.
It has been 6 days since I did any phone power/off and when I come back to my home or near my LTE tower, my LTE comes on.
I would say a LTE range around my house is about 1.5 miles radius.
If you are close to a LTE tower, your dbm should be in that great range. This is very true. See that post Robert mention.