Central Upgrade - Reset of local database - users, projects and all

I have updated the Central Server hosted on digital ocean with external volume. Post update, all the existing data has gone from central. However, as per the storage volume the data is still existing.

But, central say no project and users.

Let me know what to do to recover or safe upgrade.

The upgrade instructions work correctly for the standard installations.

How did you configure the external volume? Did you save and then bring back the configuration before and after the upgrade?