@xsy009 I find the same thing, I can see the search box, but the cursor usually doesn't appear when I click anywhere in the search box, but try typing after clicking in the search box as it shows up. Hitting enter after searching makes the search tab appear
for additional options.
Go to your folder options in control panel, and on the View tab scroll near the bottom. Mine was set to Select the typed item in the view, which I like, as I can hit first or first few letters of a file or folder to quickly navigate to it or the area, but
try changing to "Automatically type into the Search Box", now you can type anything and it goes into search box without clicking there first. If you like that behavior, it may work for you, but I prefer the other behavior. Regardless of which setting is
selected, clicking in the search box has a two second delay to respond until it does respond, then it is normal until navigating somewhere else. Then the cursor and recent search list is delayed for two seconds again.

Mine at times the search box is grayed out too, strange occurrences with the search all around.