[Zubersoft]

You can also just tap the center of the screen while viewing a score to bring up the song overlay then tap the brush icon at the top left to enter the annotation editor. If tapping the center of the screen does not bring up the overlay, that means either performance mode is enabled or you can have changed the "Overlay Toggle Mode" under Settings->Touch & Pedal Settings. To disable performance mode, tap the lock icon in the floating toolbar at the bottom right corner of the library screen. This same toggle can be accessed by tapping the bottom right corner of the screen while a song is loaded to display the quick action box.

You mentioned the search bar vanishing - that means you have hidden the filters. Tap the filters icon at the bottom right corner of the library screen to show the filters again. If you also hid the floating toolbar, you'd have to tap the three dots at the top right and then tap "Show Filters". 

Best regards,
Mike