PCI passthrough of UAD DSP accelerator card

[dust_bro]

I could use some guidance on PCI passthrough with a UAD-2 DSP card in PVE 7.1.10.
https://www.uaudio.com/uad-accelerators/uad-2-pcie.html
I'm successfully passing this card (as well as my GPU) to a MacOS VM on this server and everything works as expected, but windows VM is freezing when the card initializes.
I contacted the company but unfortunately they do not test or support any operating systems via virtual machines/environments so it looks like I'm on my own.
I've tried many combinations of bios and PCI settings, but nothing seems to work.
Are there any general troubleshooting tips that could help locate (and hopefully solve) the issue?

 

[dust_bro]

I just did a test with XCP-NG and I'm able to successfully virtualize this card in Windows 10. Would that lead to a BIOS setting or maybe memory configuration in Proxmox VM?

 

[dust_bro]

Additional info:

03:00.0 Multimedia controller: Device 1a00:0001
Subsystem: Device 1a00:0003
Flags: fast devsel, IRQ 11
Memory at 51000000 (32-bit, non-prefetchable) [disabled] [size=16K]
Capabilities: [40] Power Management version 3
Capabilities: [48] MSI: Enable- Count=1/1 Maskable- 64bit+
Capabilities: [58] Express Endpoint, MSI 00
Capabilities: [100] Device Serial Number 01-00-0a-35-00-00-00-01