Along with the issues Crono has listed
(click here to see the post), there's another annoying problem. I highly suggest all WebGL players to not clear your cache. I have and cache loads incredibly slow. Most people are still invisible for me and many tiles aren't fully loading. Tabbing out is also causing the ctrl bug to happen much more, at least on mac. Sometimes, my usual fix for this bug doesn't work. I don't know what to do about it besides mash every button on my keyboard, and that doesn't always work!