Just updated to BIOS 5020. If I enable UEFI Boot in the Boot menu, the USB keyboard is totally inoperative (in the pre-boot environment -- I cannot even hit F2 to reenter Setup! -- I have to move the jumper to the Config position, at which point I can them change the UEFI Boot option back to disabled and get the system working again). The dead keyboard happens immediately on reset (it looks like the USB ports are just not initialized at all -- yes, I've tried ALL the USB ports). This happens not only when booting a UEFI boot application (keyboard is dead in the UEFI boot application), but also falling back to a BIOS-based boot (keyboard is dead until the operating system takes control of the USB controllers). This is totally separate from the USB Legacy option (which is enabled). This is a massive regression from the previous BIOS . And makes UEFI with this BIOS DOA.
However, and just to be 100% sure, before you update the BIOS, try the following:
Restart the system into BIOS by pressing <F2> during the boot process. Once in the BIOS setup utility, press <F9> to restore BIOS default settings. Reset any customized BIOS settings. Clear all DMI event logs by setting the option to "Enable", which is located in the Advanced/Event Log Configuration section of the BIOS Setup utility. Press <F10> to save the new settings and reboot the system.