Audio out of sync when exporting to video

I am currently adding text and graphic elements onto a video, including layers that appear at a specific time in the video. At the moment, I am sacrificing accessibility by locking the playbar just so these elements remain in sync because going back tend to screw with the timing. I tried to export the finished slide to video, which should allow the user to scan back and forth without triggering any elements. Instead, I get a video with the audio out of sync. Now I suppose I can use a video editor to mute the exported video, extract the audio, then manually sync it but that would be a tedious and time-consuming process.

How can I go about this so the audio remains synced? Thank you.