Download Steelseries Engine on the pc to fiddle with the EQ. I too thought it was too Bassy so I put it on performance and loved it. And plug the dongle into the PC, don't wire into the headset to change the settings.
I did that a few days ago and it sounded perfectly fine as I said. Now I plug it into PS5 without changing a thing and it sounds awful :/ wtf?
But thanks, I will try it again with SS Engine.