The current (non insider) version is 14393 and this problem now seems to be fixed (for me anyway) so you could consider upgrading. It was released in beginning of August so if you're not being offered it automatically through Windows Update you could download the ISO from Microsoft and upgrade manually.
The process is described here Repair Install Windows 10 with an In-place Upgrade - Windows 10 Forums
I built a new system (i3-6320, using Intel 530 iGPU) and installed Win10 with Anniversary Update from the beginning, and the problem is fixed. Initially, I wasn't sure if it were the new CPU/iGPU or the Anniversary Update, but as a test I installed the video card from my previous system, and the problem didn't occur then, either, so I'm guessing it was the update to Windows that fixed it.
Every once in a while a couple icons get moved -- it is totally random -- but basically it's fixed. When the system comes out of sleep, the lock screen is 1/4-size, but as soon as I press <enter> to remove the lock screen, things pop back to normal size.
Now, if we could just get rid of the lock screen....
Did you try this? Lock Screen - Enable or Disable in Windows 10 - Windows 10 Forums
I was under the impression that 14393 was for insiders using version 1607.
We have a company managed update process so not sure when they will update us.
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