Vlad Oops, sorry about the typo. Thank you @eirk for correcting me.
Just to be sure, I also checked the iOS versions. Since they are all WebKit, all missed the two buttons on https://google.com (desktop version). Orion, Chrome, Firefox produced the same result but Safari only searches with “begins with” as opposed to “contains”.
I wonder what WebKit’s logic behind this is. It’s strange that only a very specific type of button is excluded from search. Since Orion has plans to revamp search by integrating it into the address bar, is it possible to extend it beyond WebKit’s limitation to fix this weirdness?