Same problem.
Glad to discover this thread.
Been scratching my head to figure out whatr would correlate with this behavior and see if I could devise a workaround.
First, for me, phone worked flawlessly for two weeks. Problem showed up on Tuesday. Does anyone know if Verizon pushed some sort of update just prior to that timeframe?
Second, problem shows up with/without screen protector, and with/without protective casing. I might experiment with the touch setting today to see if it makes a difference, but this seems improbable to me.
Third, for me, it manifests as a hard freeze. Battery pull is required to reset. At one time seeemed tyo boot into a "safe mode" when, upon a soft reset, booted normally.
Fourth, last time it happened, I noticed that my fingers were not only pressing the power key to start, but the way I was grasping the phone also had me pressing the volume up/down key about the same time. Wondering if simultaneous button pushes could get this into some sort of metastable state that would evidence itself as a freeze.
Fantastic phone, otherwiser. Camera is amazing. Took a high-end Nikon Coolpix along with the Samsung S5 on this overseas trip and found the S5 photos often more pleasing to the eye unless the shot was particularly challenging (deep backlighting or faster-than-usual motion)