force MacOS upgrade
if your usual apple -> system settings -> general -> software update doesn’t want to show that there’s update available, and you absolutely, positively know there is one, you can “push” MacOS to refresh list of available updates. to do so, go to terminal and execute: user@MAC ~ % softwareupdate -l Software Update Tool Finding available software Software Update found the following new or updated software: * Label: macOS Sequoia 15.0.1-24A348 Title: macOS Sequoia 15.0.1, Version: 15.0.1, Size: 1389974KiB, Recommended: YES, Action: restart, as you can see, there’s 15.0.1 update available. at this point, the GUI window should “wake up” and actually show that there’s indeed update that’s available, just like in the window below: ...