Cross dissolve at end of video not working on current project

I've made several projects and used cross-dissolve at the end to fade to black but for some reason it's not working on this one. I've deleted and re-added the transition at the end several times and cannot figure out what the problem is. The only thing that's different about this project vs the others is the addition of a separate audio track, which ends at the same point as the video and also has a dissolve transition at the end.

Any suggestions are appreciated, very frustrating! Argh haha