Android N

clear system cache. if didnt work try a facotry reset .

Check what apps are running in background. Try optimizing, had the same problem for a couple of days but once optimized and closed apps now solved.

It's intermittent.

I've done everything but the downgrade yet... Safe mode (only previous installed apps by Samsung), cache cleaning in recovery mode, maintenance storage option cleaning and soft resets every time it freezes.

The device is new and the nougat upgrade was done right after the first boot.

then try to buy new s7 😂