Hi,

Actually I can reproduce both issues you described in both 2015 and 2016 versions - lost input focus in the floating materials palette and corrupted materials palette effect when it is locked to the right side of the screen alongside with Properties and Layers palettes.

So looks like it is a defect (bug) in Materials browser palette interface.

The workaround for the first issue - lost input focus - is to ensure that mouse cursor is above the palette when you want to use search in it, because as soon as you move mouse out of the materials palette the input focus moves to the drawing area and input from the keyboard moves to it.

Maxim