Undo render and replace and attributes.

Hello. 

I’ve been working on a 1h30 timeline for days. We had a big issue with lagging on the whole project and timeline. Our IT team advised us to use Render and Replace on the audio tracks. We were able to work without any problems after that. However, I reversed the Render and Replace, and now the issue is that all the audio attributes have disappeared… I no longer have the premix from before the Render and Replace. Is there a solution? Thank you very much!