Then your permission should be set correctly.
That’s probably not the right thread. In the earlier versions the header needed to be added manually, but with NC 14.0.4 the header was added already. Usually, the check fails, if the header is set twice.
Please check here if that’s the case and the header is really set twice:
https://securityheaders.io/
If it’s set twice, this might probably help:
Or removing the header from one of the locations. I’m currently trying to find the many threads that were opened recently. If I find them, I’ll post them here.
For the DB part, run:
sudo -u www-data php /var/www/nextcloud/occ db:add-missing-indices