WS460c Gen8 not detecting AMD FirePro S4000X Mezzanine

[it61066]

My WS460c Gen8 is not detecting the AMD FirePro S4000X in Windows 7 sp1 x64; In device manager, I am seeing the integrated Matrox G200eH under display adapters but no other devices (nor unknown). In OA (c7000), I can see a Mezzanine card in slot 2 (HP MXM Mezzanine Type-B). Tried the followings:

Installed HP PSP 9.70, tested a second adapter: no change. Same problem with Win10. Latest Bios installed (2019): same issue. The strange behavior of the workstation: setting User mode in Bios is not working: if set user mode, the front display still shown (GUI).

[DanRobinson]

Reboot into BIOS/F9

Do you see the card anywhere in there?
There is a spot to disable PCIe devices, and it should be there if the server is detecting the HW at all.

Similarly you could boot a Ubuntu Live CD ISO from the iLO and then see if LSPCI shows the card or not.

Just trying to determine if this is a HW or SW issue.