My Mac running Sonoma 14.2.1 just informed me, ‘New software is ready to be installed.’ When I moused over the lower right corner of the notification a (hidden) gray ‘Options’ button appeared. With a click/hold I had the option to ‘Install’ or ‘Try tonight’. When I clicked the X to close the window the update installation did NOT start. I checked System Settings>Software Update Available and found the 14.3 update had been downloaded and showed a button to ‘Update Now’. My ‘Automatic Updates’ are configured to automatically ‘Check for updates’ and ‘Install Security Responses and system files’, that is, just the first and last boxes are checked. I do NOT have enabled: ‘Download new updates when available’, ‘Install MacOS updates’, or ‘Install application updates from the App Store’. Despite this setting, the new update (14.3) did download automatically. I don’t plan to install 14.3 at this time based on some discussions here about Apple Mail problems after 14.3.