need some help with this t-mo test drive phone

is there any way to lock this thing to lte? i keep switching between edge, 4g, and lte. all of which are two to three dots worth of signal. i have hunted around for an apn that fills in the lte settings, but from the looks of it they don't exist. this thing is currently set up on the fast.tmo apn. would switching to the epc apn solve my problems? or is this just something that has to be dealt with using the iphone?

thanks for any help :)