I have to copy paste this from notepad because I have the same issue.
Brb restart my Opera.
LOL not even ctrl-v works

I thought it was just me! It seems as if it gets stuck in some sort of mode with the right-click button or something. I can't type any text because either nothing happens or I activate a shortcut such as opening a new tab. Copy and pasting text from Notepad into a field usually gets me out of this mode. I have the same problem with Chrome and Avant, so this is a Chromium issue. I disabled the PDF plugin, so hopefully that will fix it.