Proxmox VM PCI Passthru Error MSIX PBA outside of specified BAR

Proxmox VM PCIE Passthru Error 

MSIX PBA outside of specified BAR

I created a Proxmox VM created for LLM purposes, with a NVIDIA RTX 3060 allocated to it through PCIE Passthru, which there are plenty of literature about.

Essentially,

1. Enabled "above 4g decoding" in BIOS.
2. Ensure "Re-size BAR Support" is Disabled in BIOS.
3. In PVE host, blacklist the NVIDIA drivers to ensure it is not used by the host so that the GPU can be passed on to the VM.
4. Create a VM which will use the host's virtual GPU as the primary display.
5. While the VM is offline open Hardware to add PCI device, select the GPU with all functions etc.

It worked smoothly with the NVIDIA RTX 3060.

Then...

Later I replaced NVIDIA RTX 3060 with a RTX 5060Ti, thinking that it should be a smooth upgrade because the new card is using the same PCIE slot & the VM would use the same NVIDIA driver, 

Upon replacing the GPU though, the VM would refuse to start with the following error message:

MSIX PBA outside of specified BAR, start failed: QEMU exited with code 1

I searched the Proxmox forums and other Internet articles for a solution but none of them seemed to be effective.

Then by chance I came across one line that somewhat sounded related;

GRUB_CMDLINE_LINUX_DEFAULT="quiet amd_iommu=on iommu=pt pci=realloc=off"

I had more parameters set for the GRUB_CMDLINE_LINUX_DEFAULT environment variable, but added the "pci=realloc=off".

I edited the file in

/etc/default/grub

Add the above mentioned parameter, then run

update-grub

Then reboot just to make sure, and that allowed my VM to boot up again.

Not saying this is the solution for every situation when faced with the same "MSIX PBA outside of specified BAR" error message, but at least it was solution to mine.