Error with running a VM with vGPU on Redhat Linux 7.5

Trying to run a VM with a vGPU attached to it – get an error saying “Error starting domain: internal error: qemu unexpectedly closed the monitor. But if we run a VM without a vGPU, it works perfectly fine. It doesn’t recognize the vGPU we’re trying to pass through, seems like vfio-pci isn’t initializing. Would appreciate any advice, thank you.