Having an odd problem with playback on Garageband for iPad?

I've been having a problem with the playback on my iPad's Garageband. (None of the parts were recorded from actual instruments, they're just written out on the staffs with the virtual instruments.) On some songs, usually longer ones, it will be playing smoothly, and then suddenly the last note of a bar will hang over into the next bar (making it difficult to hear the next bar), or the sound of some of the instruments will suddenly drop out, or both. For example, in one song I have 2 guitars, a bass, drums and a cello; for a while the playback was fine, and then one day I was listening to it and I heard the guitar chord of one bar drown out the next in a way it hadn't before, and in the bar after that all the instruments stopped playing except the bass. This seems like a bizarre issue and I haven't seen anyone else mention it. Does anyone know what the heck is going on?
Asked May 16, 2015

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