UEFI enabled, no UEFI boot options showing on Precision T3610
We have 2 Precision T3610 computers and want to do a fresh install of Windows 10 in UEFI mode. One computer worked using a Win10 FAT32 (UEFI-compatible) USB key and is successfully running Windows 10 booting in UEFI. The other doesn't show any UEFI boot options with the same USB key installed, same BIOS, same options set.
Tried front and rear USB 2.0 slots, tried 3 different FAT32 Windows 10 installation keys. Current BIOS A14 on both computers. Tried downgrading BIOS to A13, still no options (only Legacy boot options show up even when in UEFI mode). Cleared CMOS with jumper, still no options. Upgraded BIOS back to A14, still no options.