Ubuntu 20.04 and single GPU passtrough

Hi forum, I’m trying to pass my Nvidia RTX 2060 to a windows VM running on an Ubuntu 20.04 host. I’ve gone trough several guides (for example joeknock90’s) and at the end all suggest the same steps which I’m following with no joy.

I’ve then tried manually running all the steps listed (stop the DM, kill gnome sessions, detach console, framebuffer, unload modules, detach the PCI devices, etc,etc). I end up with a black screen (but monitor active).
Then I run the VM passing the PCI devices of my iommu group, after a while the monitor show no-signal and goes in standby.

I’m pretty sure I’ve followed the direction correctly and the log does not show any error or warning so I’m a bit lost. Any suggestion on how to troubleshoot?