Here are some screenshots after install of Lollipop 5.1 on HTC One m9..
It appears that in addition to the undefined LTE when in the lower position, in some cases, the Sprint Band number is also shown. We just have to know it.
The first two (2) screen shot is identical to before installation of the upgrade from 5.02 to 5.1
Now ... In some cases, ..., NOT ALL, reading the lower limited display may tell you the Band, PCI, etc of the tower that LTE is being seen on. In this case Sprint Band 26. The same may occur for Sprint Band 41. If it is Sprint Band 25 the band number will not show, but the PCI to identify the tower may or may not..