a couple minor problems...
first, your layout 1 would have the same issue if you sit on layout 2 for a minute - listening to the music before pressing Play.
You need to set StartTime at the beginning of each layout that needs it. the system Time variable starts at zero and automatically increments every second your game is running, regardless of the layout you are on. So, when a new layout starts, you want to set your variable to Time, so you can calculate the correct offset from that to make your text appear.
You don't want to set StartTime=StartTime + 1 every tick, because every tick happens 60 times a second, so you will very quickly end up with a large value that doesn't help you.
I fixed eventsheets 1 and 4 to work the way you want.