Why doesn't clicking with the mouse on an item in the search history not move the item into the search window?ry

When I start to type in a search item and the auto-complete offers choices and I click on one of the choices with the mouse, the history disappears and nothing is added to the search bar. I am left with only what was there before the auto-complete offered choices. Before the last few days, when I clicked on an item in the history window, it would move to the search bar. I tried moving the mouse to the item and then hitting the enter key on the keyboard and it moved into the search window. I haven't changed any settings. Why did it stop working with a mouse click? Thank you,