Clip gain change not visible in Logic 10.8.1

I changed a clips gain from -24,7dB to -2,7dB using the file editor. First +12db, then +10db.

Everything worked and the waveform got clearly bigger as it normally does. I edited the clip and saved the session.

When I reopened the session, the file was still -2,7dB but the waveform looks like the original -24,7dB file.

Why is this? What can I do?

I believe this particular quality has come very recently. Maybe with the 10.8.1 update.