This issue is fixed in System Software 1.1.0.
During system boot, the main Power/OK LED transitions from a steady blink to solid once it has started booting an operating system. When the system is configured for UEFI Boot Mode and begins booting to an operating system that supports UEFI Boot Mode, the Power/OK LED remains in steady blink mode and does not transition to solid.
There is no workaround. The system functions normally and the blinking state of the Power/OK LED can be ignored.