Thanks all for replying! I knew these two workarounds, but they're not as convenient as before. Previously after doing a scoped search, I could return to all notes just by two continuous clicks, first on the "Clear" button and then on the "All Notes" button. They are placed at the same place. I could return to all notes in 1 second. And now, it's at least 4 second... As I have so many notes, I cannot accept this overhead.
This button is convenient for me. I know I could still click on the menu and select "All Notes", but for an intensive user, this one more step is too much for our everyday use! Please consider get it back!