Each Virtual program contains 8 releases, the algorithm picks blind one of the 8 releases within each program without any reference to what was selected before, so there is a chance that the same release will repeat or even play 3 times in a row, due to only having 8 to choose from.
In App version 1.13 there will be functionality to view what releases have played. If a release has played 3 times in a row please contact support and they will take a more detailed look into your playback history to make sure there is no underlying problem.
Lastly, please check you have all 8 releases of each program downloaded onto the iPad. If only 4 have downloaded, there is a greater chance the same release will repeat.