Have you tried it with the nvidia card disabled, monitor connected to the on board port (driver/software updated).
Suppose you have read/followed the PVT help articles.
My PC- Ryzen 5 5600x, B550 aorus pro ac, Hyper 212 black, 2 x 16gb F4-3600c16dgtzn kit, NM790 2TB, Nitro+RX6900XT, RM850, Win.10 Pro., LC27G55T.