All contacts gone (macOS)

Nextcloud version: 18.0.7
MacOS Catalina.

note: this is probably more a MacOS question, then a Nextcloud question

Heya, I wiped my Debian VPS with Nextcloud and reinstalled a fresh new version.
All is working well except one thing that went wrong.

Before wiping the VPS, I backupped my contacts from the MacOS contacts app using the build-in export function. This created a lovely file named Contacts - 04-09-2020.abbu

After reinstalling Nextcloud I wanted to import the contacts, but found, to my horror, that only the local contacts were saved in the export.

Is there maybe a sneaky, extra file somewhere on my Harddrive where I might find the other contacts that were synced with my Nextcloud? After all, my nextcloud contact were also available when I had no internet connection…

I did try to revert to an older copy of ~/Library/Application Support/AddressBook, but that did not help…

I have multiple backups of my HD, so I can go back in time if needed.

I do not have a backup of the wiped Nextcloud…

Thank you all who can help me with this.