Same problem. Makes https://yandex.ru/maps/ and https://www.google.com/maps/ completely unusable. https://soundcloud.com/ has this problem too but it's less intense.
Problem seems to be connected to loading new data, and while it happens opera's task manager goes insane with tasks flickering all over the place. Flickering stops when everything is loaded, but comes back when new information needs to be loaded i.e. new map region or new song.
Bug only appeared in newest version. Never had this problem before.
Edit: hardware acceleration was off. enabling it fixed the problem