I am trying to restore/reset an Apple iPhone 6 Plus which has had the password entered incorrectly too many times.
I have plugged it into my laptop for the first time and entered iPhone Recovery Mode.
My MBA, running macOS Catalina, shows "Your Mac is downloading a software update for your iPhone and will install it when the download is complete".
It sits like that for around 15 minutes then the message disappears and the iPhone reverts back to "iPhone is disabled. Connect to iTunes".
What am I doing wrong?