MacOS Big Sur update not initiating
I have a macbook air mid 2014 on which I tried downloading the big sur 11.4 version from appstore, what is downloaded is just 28 mb. Tried running it, was able to click on agree to terms of software licence agreement, then clicked on continue when it said that it will be intalled on macintosh HD and this is where it stopped. Nothing else happening, no download initiating. Tried erasing and dowloading again, doesn't help. Tried terminal: softwareupdate -fetch-full-installer-version 11.4 and it didn't do anything. I also have 50 gb of free space.
iPhone 6s