No autofill option showing for 4th gen IPod on Itunes

When loading 4 gen shuffle (v 1.0.2) from music library on Itunes 12.0.1.26, the "settings" and "autofill" buttons do not show up on the On My Device>Music page. I want to be able to have it autofilled randomly from my music library. Oddly, it loads it randomly by complete album; that is, it loads all the songs on an album, then randomly selects another album and loads all the songs from it, etc., until filled. Any idea what the problem is?