When you are playing, the piano keyboard dosn`t show the keys

Hi, I played a sheet, I pushed the play button and the program played correctly the sheet. The problem is that I forgot to show the keyboard, and then, I pressed the key "P", and the program showed the keyboard, but the keys didn't follow the music, and the keys were stoppped, without movement. I pressed the button Play twice, and the program worked correctly. I think that could be great, if you press the key "P" and suddenly, the keyboard follow the notes in the sheet.
Many thanks.