Does the word "array" exist within the note body of that first note you highlighted?
As:
For example, searching for cat will return all the notes that contain this exact word. Note: it will not return the notes that contain the substring - thus, for "cat", notes that contain "cataclysmic" or "prevaricate" will not be returned.
As for the codebock thing, this seems to be upstream in TinyMCE, it does the same thing in their demo:
