Volume reverting to low on some audio imports after opening


I have noticed on a few projects now that some of my imported Audio files are somehow being reduced to ‘off’ in the Sound Element Editor. The current project I am working on, I have two characters with audio broken up into separate parts for each scene, and every part of one of the characters is being reduced to the lowest part of the volume slider, so no audio can be heard. Even after increasing the audio back to the correct level, when I save, close and re-open, all these audio parts have again been reduced to the lowest setting on the Volume slider.

I have seen other people posts in different areas regarding this problem but they have not determined why this is happening. I am using Harmony 15.

Any help would be great!