Phone [Q] Is There An Update Coming Soon For Galaxy S5 Verizon?

I have the Galaxy S5 with model# SM-G900V and it is serviced by Verizon. My phone currently has Kitkat 4.4.2 on it and I have tried to check for version updates and nothing yet, it says I'm up to date. In the month that I have had this phone I have been experiencing drop calls, network speed bouncing around from 4G LTE to 3G and back then down to 1X sometimes I have to restart my phone to get my network speed back to 4G LTE, also when I press the home button sometimes to wake up my phone the screen stays black but the light up touch buttons at the bottom next to the home button light up. I have to press the power button once or twice to get the screen to light up. Are these common problems for the S5 or is my device defective and needs to be replaced?