Going back to 12.14 here also. This is sick. If there will be no workaround Im going to firefox.
By the way. There is an addon:

https://addons.opera.com/pl/extensions/details/searchbox-toolbar-for-opera/?display=en
which could possibly get rid of the problem, but:

1. It is discontinued
2. Somebody would have to write adding new search engine
And this could be a solution/workaround.