Files deleted after Backup, maybe Update

Hi guys.

I’ve been using Nextcloud for a couple of years now and I’ve made a fatal mistake in the server migration.
I had to install a backup of the VM from December 2017 and unfortunately had not turned off sync on the client. I´ve made updates from 12 to 14.
Now all the old files are changed with the current files on the client.
The activity log states stands they have been deleted.
There is nothing in the trash bin, so where are the files ?
Can I restore them?
Thank you in advance.

Kind regards,

duplicate of Vergessen Sync abzuschalten und nun sind Dateien weg