Im on 4k OLED 55 inch and i can said you it’s just impossibl for you with your screen computer to achieve my quality level , black level and Hdr level . On the oled screen the hdr is just amazing.
Jamezdg what is exactly the model of your Tv ? i can give you some tweak to get the best 
I have exactly the same setup than you . ( 3800XT instead of your 3700x )