Can't say I've seen that behavior, but then I usually disable sleep because I find it to be an unreliable shit-show on EVERY blasted OS. Don't get me STARTED about having to run modprobe every damned time I boot into some flavor of linsux just to get the second display recognized and the primary display to run at anything other than 800x600. Then people wonder why I say linux and pretty much all *nix implementations haven't even caught up to winblows 98 on basic functionality.
That and displayport is just pissing me off. I don't even have any displays that support it -- not even my year old 4k 65" TV has one -- and it's a PITA to get displayport narrowed down to dual link DVI for my 27" 1440p that's the primary on my workstation.
I finally get TWO current gen video cards, and I'm having to use a half dozen dongles to turn this displayport crap with its even cheaper and rinkier connector into something actually useful.
Displayport's similarity to the cheap-ass rinky-dink tinkertoy garbage that is SATA isn't lost on me. It's sad when the people designing these connectors seem to have just one goal: Making micro USB look robust.