Editing music is jumping around

An odd way to title this but I am baffled with project. More tbh one problem.

First, I had to start with laying down an audio track because I needed it to serve as thematic bed for photos and video I would be tying to parts of the music. I edited down two different tracks but in one split clip section, anytime I try to edge it closer to the previous section (to close.a gap), the previous section disappears or droops to a level below all on its o. STYhe same thing happens when I start to dd photos. I've pretty precisely edited this audio track, so I don't want to mess it yup.

What am I doing wrong?