The Lighting Controller

Hi Everyone!
using ShowXpress on Mac.
I have a Timeline with a length of 0:11:00 minutes with an audio track to match.
The first 5 minutes i have successfully been adding light Scenes across the timeline using the Red & Green Markers to cue things up.
Now when I use the Markers after 5 minutes they don't sync up correctly with the light Scene timeline.
It's as if the Timeline is confused as to where the Markers should actually start.
Tried .Wav and Mp3 for audio.

Thanks for any help!

Would it be possible to upload the WAV file (not the MP3) in a cloud-based file transfer service (like "wetransfer"), and post also a zip of your lightshow ?

All good now. I'm on a newer Mac now and the .wav is lining up nicely.
Thank u!