It is official, @Vivaldi have included advertisment into your address-bar suggestions. This is opt-out, so it is enabled by default and is triggered only after two characters in your address-bar.

For me, the address-bar in a browser is like terminal in Linux, what I type is sensitive and should not be cluttered with advert and junk. #Vivaldi crossed a big red line here. Having advert in favorites and quickdial is one thing, having advert in address-bar is another.

https://vivaldi.com/blog/what-is-direct-match/

What is Direct Match? | Vivaldi Browser

Let's find out how Direct Match, a new functionality, helps save time and reach the website of a familiar brand from any of our search fields.

^{Vivaldi Browser}