Audio track with 6 channels volum adjustment problems.

I have Audio tracks from AVCHD files that have 6 channels. When I want to make volume adjustment, I have control over only 2 of those audio channels inside that audio track. How to adjust volume of the others 4 channels?

I have several hours of work done on that projects, I don't want to start over again. It seems something happen in this projects, since when I open a new projects to test with the same files, I have control over the 6 channels of the audio track.