Sounds more like the shift key got a keydown event, but no keyup event, handled poorly by libcef.
I regularly get this issue, and yes usually pressing SHIFT solves it.
I use highlighting when I read through the text in the steam client, because the font is small and cannot be resized. This bug effects me multiple times a day. It is very annoying.
Ubuntu 16.04 64-bit
I have this issue as well, but on my library as well, not just the web browser. I didn't know "Shift" could fix it, I usually just restarted the client.
Nothing extracted yet.
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