Version: 4.8 Preview 1 (Version: 4.8.0-2536902+++depot+UE4-Releases+4.8)
Launcher Build on Windows 7 x64
Inside the any Blueprint, selecting the a Component works as expected - the Details Pane shows all the stuff exposed to us. But whenever a property is changed, some sort of refresh happens that makes the Pane lose focus for a brief amount.
The most obvious one is the Movement Component of a Character (either the default one, or a derived one such as the Rotation or Projectile Movement), where changing a value (for example, toggling “Can Walk off ledges” from default on to off or changing the walk speed to a different value) causes the Component to lose focus/become deselected and the Details Pane is cleared.
This tends to be very annoying during the initial setup of a character; especially when fiddling around to get just the right values.
But this also happens for other Components, most notable reproducible with ones having a spinner-control that allows for MouseButtonDown-DragAround to change the value (such as Camera FOV, SpringArm Length, Arrow Size or even Rotation). Doing that (for example, clicking into the Size field of an Arrow component and dragging to the right) causes the change to be accepted of some sort, but the editing stops immediately and the Viewport tab flashes briefly.
Doing the same in the main editor viewport gives a smooth change with immediate preview, as it did in 4.7.