Logitech K360 wireless keyboard unusable to enter drive decrypt password at boot

Hi :)

Have to put a wired keyboard in order to decrypt the hard-drive at boot as the wireless keyboard simply is useless at this point. Wireless keyboard recovers its usefulness once past that point. The wireless keyboard can access BIOS beforehand, no trouble there. Motherboard is an M4A87TD EVO with an AMD 870/SB850 chipset. Using USB 2.0 for the keyboard receiver (Logitech K360 with the Logitech Unifying receiver).

1. LinuxMint 17.3 Cinnamon edition, upgraded from 17.2; initial upgrade did not include this regression, not for a few weeks.

2. Reproduced after installing on a flash drive - meaning I unplugged my HDD, put in a 16GB USB key to install LM 17.3 on it using another USB with the live installation on it; installed it as a fully encrypted disk as was the case with the HDD. Booted without the HDD and the problem is consistent.

3. Steps:
a) Boot, no response from keyboard at decrypt password prompt. Ctrl-Alt-Delete does nothing. Hitting power button does nothing (I would expect shutdown sequence, but I guess not, so five seconds button push to shut down or reset button). I thought the computer frozen at that point.

b) Reboot in recovery mode with 3.19 kernel; no response from keyboard typing at decrypt password prompt. Ctrl-Alt-Delete does nothing. Put USB key in and see it show up, but nothing else happens from keyboard.

c) Reboot in recovery mode with 3.16 kernel; no response form keyboard typing at decrypt password prompt. Ctrl-Alt-Delete does nothing.

d) Plug other keyboard with USB cable, and lo and behold, HDD mounts, goes back to normal at that point. Wireless keyboard becomes useful again.

4. What should happen : being able to use said keyboard. Will test with wireless Microsoft Arc Keyboard and report back.

5. Problem is persistent at every boot, without fail.