UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36

Steps to reproduce the problem:
1. open browser
2. minimize it
3. turn off screen power (power settings> power button)
4. power on screen again (move mouse, etc.)
5. hover mouse cursor over taskbar icon for chromium
6. hover mouse cursor over preview popup thumbnail
7. both views are now blank - do not show contents as should
8. no other apps, etc (edge, firefox, win expl, others) blank out
9. restore window then min again, contents return to views
10. power off screen > blank again.

What is the expected behavior?
to show window contents (tiny version) in thumbnail & full window on expand (hover on thumbnail flys out full window). check other win10 pro 64 apps

What went wrong?
thumbnails & flyout full windows go blank (do not show the window contents). no other applications or windows tested so far show this blankout behavior.

Did this work before? N/A 

Chrome version: 66.0.3359.181  Channel: stable
OS Version: 10.0
Flash Version: 

extremely annoying and negates a huge interface improvement in ability to view contents in taskbar icons to search for desired items vs having to expand every window to see what is in it. big waste of time. since I found that other browsers (chrome does this too so it's a chrome issue) like edge & firefox do not fail, i'll be using them instead now that edge is half-way decent. i'm not holding my breath on you doing anything about this. i have spent 10's of hours searching for a "fix" to no avail.