Update
With kernel 4.4.0-81 it seems to work well again, without myself doing anything extra to fix it.
Everything was working fine until a little more than a month ago, there were multiple kernel updates and Nvidia driver updates during that period so I'm not sure which one caused this problem.
I get the distortion below in the screen after starting the machine from standby (goes away if I restart/log out and log back in), it's shown around any window that is not maximized, around dialog boxes, around menus, basically around any edge on the screen.
I'm currently running kernel 4.4.0-77
and Nvidia driver from the package nvidia-375
PS: switching to the other driver causes other problems, and this one was working very well before this issue, and it had been running properly for months before this problem started happening.