After you tap an album in the Library section of the Words game to include it in the game, please don't forget to deselect the albums that you don't want to be included.
It may require scrolling to the bottom of the library and checking all of the subsections.
Then tap the arrow in the top left corner of the Library to go back to the home screen and play the album.
Please note that custom albums can only be played in the Zen, Zen Junior or Versus modes, and not in the Adventure mode.
If that doesn't work, please try reinstalling the Words app, restarting the device and updating the OS.
If the above doesn't help, please write us at email@example.com with a screenshot and the myOsmo URL of the Words album that isn't working for you!