What's the resolution of your monitor, what are the graphics settings you are using in game?
The reason I ask, is that I moved up to a 1440p monitor several months back and that kind of forced me to upgrade my system, from a i5-6600k, gtx 1080, to a i5-12400f, 6700xt, because I would get poor frame rates in certain situations within the game with the 1440 monitor where I didn't with a 1080p monitor.
The only thing I can suggest is to turn all your graphics setting to performance, set environmental map to 0, turn off shadows, reflections, and anything else that is not required, and see how that effects your frame rates.
