I'm having the same problem and wrote about it on a Reddit page where a number of other people are having the problem with their S7's also:
https://www.reddit.com/r/GalaxyS7/comments/5xx705/after_nougat_s7_keeps_getting_unresponsive/
No solution so far
I wrote:
"I also have this problem with S7 on Nougat which started about 3 weeks ago. It seems to be getting worse.
A couple of times where I've ignored it the S7 got so hot I actually thought about keeping it away from my person. I can always force restart it by Power+Volume. Mostly I can wake it up by pressing the power button and the screen will light up after about 10 seconds of waiting, but nothing responds.
Once I had it happen while using the device. When this happened, I noticed that swiping down the notification bar sped everything up temporarily. If the notification bar was hidden the current application would be laggy. If I swiped down the notification bar partially the application would render quickly as normal.
I've also found that Google Maps and Spotify are the two main apps when this happens, but a common link for me is that either one will be connected to bluetooth in the car or bluetooth headphones. I don't think it's ever frozen without bluetooth being connected, but that could just be coincidence.
A strange thing is that Spotify stays playing songs and responding remotely when the S7 has frozen. If I have Spotify open on my laptop controlling music on the S7, I can still skip forward/pause/play etc for ages, although the songs start skipping audio after 10mins or so before stopping completely. It's like the System UI is the problem on the S7, and the app itself is still responding?
I'm wondering about doing a full reset but I'm dreading the several hours of setting everything back up, without knowing if it will solve the problem.
I use Lightflow and I'm going to try uninstall that for a week and see if I still get the freezing, simply because it is the only app that is continuously running on my phone in the notification drawer."
