I have done the same type thing as Tom Baldwin6. I "redid" my phone using the Verizon software installation assistant and did a "repair". I then rooted it using TWRP, and started adding stuff. I have not had the problem again as of now.
I was thinking it was the experimental app that was allowing me to mirror my phone using Chromecast, but I am using version 4 of that app and it is still working. I used version 5 before.
My phone hasn't had a problem again after 24 hours, but as I continue to add apps and check, eventually I may find another culprit. I will post here if I get it tracked down.
Droid Maxx 1080
and Asus TF101 Transformer
Android 4.4.4 KitKass Rom