Show Cue System

Hey gang.
I'm currently running a dance show running SCS with MA2. We have noticed that the timecode started off in sync, and now after about 30-40minutes it seems to be ahead a full second.

No pre Roll, no timecode Starting at different times. It is in a sub cue with the audio file and is about 1 full second ahead. Can someone help or is there a way to force the timecode to fall back or Re sync with the audio track. We are also running a video file in the sub cue as well.

Thanks

Is it possible, that the timecode ended up locked to the video content instead of audio, and so you needed to be using a drop-frame timecode format?