Accent-sensitive searching is on
The problem with the search is that you have accent-sensitive searching turned on. If you look at the 5 boxes immediately below the Command Line, you see that the 3rd box is yellow. This is an indicator that the accent-sensitive searching is turned on. You can place your cursor on that box to see the options that are set.
To turn off the accent-sensitive search, right-click within the Command Line and uncheck the Accent-Sensitive Searching (Greek) option toward the bottom of the list.