Libreoffice hidden files

Nextcloud 12.0.3, CentOS 7 Apache 2.4.X, PHP7.
Desktop client on Windows 10 fully updated.

Here are some pics,

I was editing a file with LibreOffice Writer, and Nextcloud synced all the .sync files. So if I delete them it cannot because Nextcloud has them open. And they do not show up in the Nextcloud browser.

If I shutdown the desktop client and delete them the moment I turn the desktop client on, they reappear and I still cannot delete them.

How do I get those files deleted? This could damage my file if I open them with those files present.



Are the .sync_db files part of Nextcloud and not Libreoffice?

Yes, these .sync_db files are part of Nextcloud. They contain the database of which files have been synchronised to the cloud.