sometimes I have to manually force lte on using the lte onoff app or similar. although, as said above, the lte is down. if you are getting 1x, try lte only with voice, if that doesn't work, try cdma auto prl.
If that doesn't work, then most likely, it means lte and ehprd (3G) are down. you can force it to rev. A (3G) by doing the following and it may work.
I would get use to it all of the carrier's are having issues with the smartphone boom. I am loosing signal at my house even with a network extender I sometimes get no signal. I contacted verizon and they told me that the bandwidth is being used up with so many activations in my area. They gave me the opportunity to let me out of contract with no etf fees on six lines. I always had five bars here for the last six years.