I am having this exact same issue. I thought it might be my old Macbook Air, but I am so releived to see that it is happening for other users as well. This does coincide with the freezing tab preview behavior, and also I've noticed that the main close window button doesn't work either- you have to double click to close all the tabs first before you can close the Opera window.

I am having this exact same issue. I thought it might be my old Macbook Air, but I am so releived to see that it is happening for other users as well. This does coincide with the freezing tab preview behavior, and also I've noticed that the main close window button doesn't work either- you have to double click to close all the tabs first before you can close the Opera window.