Same problem on 2 devices. Every time I'm plugged in and try hovering over the previews they just disappear way too fast. When I unplug, they work properly as they do on my other 10 computers. By the way, my battery meter works 100% perfect by the way, no changes or statuses or flashes or anything, just rock-steady at 100% "Fully Charged". So it's not an issue there.
Summary of the problem in basic terms:
- When plugged in, the taskbar icon previews disappear too quickly to be used (sp4 keyboard).
This is true when clicked or when hovered, when stationary or moving, etc.
This problem is very simple and very obvious. I have all the latest updates, but it occurred before I got them too.
I can create youtube videos showing it, but it's so silly simple that you're not going to get any more info than that. Pen hover works properly, so it seems to only be an issue with an attached keyboard (including the SP4 keyboard) or USB mouse.
I suspect every Surface Pro 4 and every Surface Book in the world have this exact same problem. It's kind of a fundamental Windows feature to be able to switch windows with the task bar, but with my super quick reflexes I can sometimes nail it just fast enough before they disappear to get my work done (or resort to alt+tab or Win+tab).