QNAP replied. It is a bug.
Dear Customer,
No action is required from your side in the meantime. There is no need to manually copy any entries from
/etc/default_config/uLinux.confto/etc/config/uLinux.conf.The system will manage these configuration files automatically. As mentioned previously, the Container Station QPKG was incorrectly reading the values from
/etc/config/uLinux.confinstead of the correct/etc/default_config/uLinux.conf.The fix for this issue will be included in the Container Station 3.1.4 release. Therefore, the configuration files should be handled properly by the system, and you should not need to manually edit or synchronize them.
Thank you for your patience.
So I am going to reset /etc/config/uLinux.conf to default and wait for next container station release.
Overall, I find QNAP support to be very good. Inquiries are taken seriously.