SR-IOV toggle has no effect on CW-NAS-AMD-FP7-4L

Device Model
- Motherboard: CWWK CW-NAS-AMD-FP7-4L (AMD Ryzen 7 8845HS)

- BIOS: FMA01_P5C9V18 (2025-12-24)

- Add-in card: Intel Arc Pro B50 16GB (PCI ID 8086:e212, subsystem 8086:1114, firmware BMG__21.1182)

- OS: Proxmox VE, kernel 7.0.14-8-pve

Issue Description

Symptom: SR-IOV is not available despite "SR-IOV Support" = Enabled in BIOS. No device on the board, neither the B50 or the four i226-V NICs have exposed SR-IOV capability to the OS. I can see the SR-IOV capability in the B50 config space, but the BIOS unlinks it. 
I have tested to toggle SR-IOV to disabled, boot, and then enabled again, no change.
IOMMU is active, I get 46 IOMMU groups. ReBAR is enabled, B50 reports Physical Rezisable BAR, but not Virtual Rezisable BAR.

Is this a known BIOS behavior on the FP7-4L? I havent found anyone else mentioning this issue on this board so I am uncertain if I'm doing something wrong.
Please advice, I'm happy to test any build you can provide.