I've got a Tmobile Note 7. Mine seems to often not detect that I've tapped on something, and takes another tap or two to finally register. Other times, it'll be sluggish with scrolling, pulling down the notification shade, opening recent apps, and general on screen animations. The Samsung keyboard is especially bad.
The phone goes through almost no battery when asleep, so it doesn't seem like it would be something keeping the CPU active. This feels like either some sort of over-aggressive governor or some kind of conflict with data transferred to the new phone over Samsung Smart Switch.
I've rebooted multiple times, cleared app cache partition, changed animation scale to 0.5, disabled numerous Samsung bloat apps, nothing has helped. The issue started about a minute after I left the store, so it wasn't caused by any of this troubleshooting. Add this to the heat-up issues and unimpressive battery life when in use, and I am one frustrated dude. My S6 edge+ was leaps and bounds ahead of this thing.
