This is very annoying. I decided to do a clean install for my new MacBook, so some other tweaks that I apparently had from years before were lost. I guess.
But, one of the things that was very annoying on the new MacBook was that when I searched from the address bar, Safari was requiring me to press Enter twice. I was used to pressing it once.
Here is the fix:
Go to Safari Preferences, Search and disable “Include search engine suggestions”.