I find save button always remains disabled on page: Home > Stores > Settings
I am using Version 220.127.116.11.
Even when I change details in any of the setting tabs, the save button remains disabled.
Check (i.e. remove) something that you might have added to edit your admin - specifically - settings. It does take a second or to to work, but it does change on default theme with no extensions to alter its functionality. It could also be your browser.