I use a [[ https://web.archive.org/web/20160328131338/https://www.yubico.com/products/yubikey-hardware/yubikey4/ | Yubikey 4 ]] with a static password to login to full disk encryption at boot. On my other computers, it works fine. But on the Librem 15 version 4, it does not consistently reproduce the same characters. The resulting characters randomly alternate between the expected characters and their corresponding SHIFT characters, for example characters a or A, or characters 5 or %. I confirmed in gedit. Just to confirm, I tried in all four USB ports of the laptop, I rebooted a few times and tried again, and it's the same inconsistency.