I want to let you know that the April 22, 2022 BIOS 1.2.1 update has resolved the PCIe 1x4 slot issue. We were able to install our 10GbE NICs onto the motherboards with no further hiccups.
So, this is following up on the Elgato 4K60 mk.2 capture card not showing up when installed on the top x4 PCIe slot.  Been troubleshooting this with Elgato and at this point they haven't been able to find a reason it why it isn't working in the R13.  I finally fished out my NVME PCIe adapter, put a working NVME m.2 drive on it, and that isn't showing up at all either.  It's getting power, just as the Elgato card did, but isn't showing up as it does in the other system (same with the Elgato). I'm on the latest 1.08 bios and I don't see any options to manage the PCIe slots.  Any suggestions would be greatly appreciated.
Aurora R13, PCIe x4 slot not working?