This has happened a couple of times now. The worst occasion was last night when I was going through a user bank listening to the preset sequences on the patches. I altered one to something different and then played it back and then moved on to the next patch and obviously it carried on playing because I hadn't turned the play off. BUT even when I turned the play off it carried on playing and did so for every patch I selected, even if I pressed the Play button again.
I'm on the latest firmware.