I had my high pressure fuel pump replaced and haven't had any issues since. I've also swapped to E85 for the last 3 1/2 years since its almost always a $1 cheaper in town.
*UPDATE: High pressure fuel pump needed replaced*
I just began having the same issues posted above in my 2014 LTZ and have only run 91 octane since getting the truck (almost 80000 miles). Has the answer for most truck owners been the injectors getting varnished?