Hi Gilma,
We tried repeating what you did, and apparently this is a bug in the current LR version -- karma to you for pointing this out!
What happens is, LR "ignores" the Override settings you have set and still follows the Playback Setting of each individual Playlist. Temporarily, you can just do your preferred playback setting for each of your playlists so that LR will play them the way you want it to work.
Please note that this bug only happens in Playlists. The Override settings work properly for everything else (Courses and Categories).
Rest assured that we'll get this bug fixed in time for the next version of Little Reader.
Thanks again, and sorry about this problem!
Cheers,
Kezia