@ysery We do have a version control that is enabled for the paid version where the changelog would help to restore to an earlier state of the collection. This document here should provide you details on the same.
We apologize for the inconvenience caused, our team is diligently working towards fixing the issue. Meanwhile there is another workaround that might help - the app does take regular backups and are stored locally, you can find the same by navigating to the “Postman” folder. You can import these into the app to see if you can recover your collections including the body. You should be able to locate them based on your OS:
The files should be named like:
backup-2020-05-04T17-30-46.915Z.json. If you don’t find the body in them, try with other backup files (going backwards, based on the timestamp of the backup). Hope this helps!