Oh this is interesting; right click and "open in new tab" seems to work, but cmd+click (my preferred method) doesn't. They must have something else going on that interferes with it, very strange.
I'm on MacOS; I think I found the issue in the code they use for navigation. It's checking for ctrlKey on the MouseEvent and not MetaKey as well, which is what CMD maps to on MacOS. I might email them about it.