Anyone with a concern for keeping their data local or private, Nextcloud is a great solution. They have come a long way since they forked from ownCloud. Recently, I updated my installation to version 14. Afterwards, I had to update a few database indexes (see below) and then came across a security warning.
chmod +x /var/www/nextcloud/occ
sudo -u www-data /var/www/nextcloud/occ db:add-missing-indices
Start of the security warning after updating:
The "Referrer-Policy" HTTP header is not set to "no-referrer", "no-referrer-when-downgrade", "strict-origin" or "strict-origin-when-cross-origin".
If you have Nextcloud, give the scan a try!