I am dealing with a similar issue outlined in the following articles:
https://www.symantec.com/connect/forums/endpoint-encryption-keyboard-not-working-properly-boot
https://www.symantec.com/connect/forums/usb-keyboard-doesnt-work-bootup-passphrase
https://www.symantec.com/connect/downloads/sep-policy-block-usb-and-exclude-keyboard-and-mouse
The difference is, I am on SEE 11. I have a Dell Latitude 7480 connected to a WD15 Dock. When the system reboots, the SEE passphrase screen appears, but the keyboard does nothing. If I plug the USB keyboard directly into the laptop -- instead of the dock -- I can use the keyboard. I have updated the dock drivers and firmware. I could not find instructions for creating a custom hardware compatibility patch for SEE 11. My EU is working around the issue, but I will probably see a number of these reports popping up. Thanks in advance for your assistance.
I have the same problem. the only difference is that hardware - these are Lenovo Thinkpads T440.
Anyone has found any solution for this?