Several Renesas evaluation boards come with a J-Link-OB-S124-Renesas on them which allows out-of-the-box debugging on these boards without an external J-Link being connected.
Initially, all J-Link-OB-S124-Renesas reported S/N 831004110. This made it impossible to have 2 or more eval boards connected to the PC at the same time.
With V7.66e of the J-Link software, a firmware update was introduced that auto-assigns a unique S/N of format 831xxxxxx to the J-Link OB. So with updating the firmware to >= V7.66e the S/N of the OB changes once.