1. Make a backup of the current site just in case before we start – go to Settings > Site > Export site to download just the site backup file.
2. Delete the site you want to restore an older version for from the current controller under Settings > Site > Delete.
3. Take a backup of the whole server under Settings > Backups.
4. Restore the old server backup to a new, temporary controller. You can install that on your Windows or macOS PC: https://www.ui.com/download/unifi/
5. Once the restore is complete, export the site backup file you want by going to Settings > Site > Export.
6. Restore the whole server to the backup you took in step 3.
7. Import the site export file under the sites drop down, Import site.