Most people running multiple monitors with a Windows PC have run into a bug where Windows arbitrarily rearranges apps across both monitors when returning from sleep. A Windows 10 update will fix this.
If you use multiple monitors with Windows, you’ve probably encountered this frustrating bug: When your PC resumes from sleep, all your application windows arbitrarily rearrange themselves. Microsoft is finally fixing this. Microsoft calls this Rapid Hot Plug Detect (Rapid HPD), and it tends to affect multi-monitor setups that can use the DisplayPort interface, or that run DisplayPort over another cable, like Thunderbolt.
