I don't know if this is relevant but I've recently received a couple of E9+ and couldn't access. They were not showing with any ip scanner.
If you have the same problem... hold reset button for 30 seconds and release. It will reboot and then will show up with any ip scanner.

You will have to put the speed back up to 750 PLL as that will also reset to 600 and only run at 7THs or so