I have noticed that the web UI does not always show what the player is doing. Not sure if it is a bug, or something related to the Raspberry Pi, or to the Android phone I am using. I described one previous case here:
In this screen shot, the queue screen is showing both tracks, the one I selected, and the one playing... this may just be another example of the same thing, if so, then please ignore...
I am wondering if this happens because my Pi only has a WiFi connection? This was all in one room, so the signal is normally pretty strong, even though the data rate is slow. (The data rate over WiFi is not an issue for me, since it is more than fast enough to stream most audio files.)