What was previous graphics card, did you use DDU to cleanout/remove those drivers?
Did you try with just 1 monitor connected to graphics card, not output from motherboard.
Did you change the 'initial display first' setting in motherboard bios to graphics card, if your cpu has graphics & enabled.
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.