That is strange. But perhaps you have turned something on to do with DLSS and because it is not implemented, that is why it is giving problems?
Also, your hardware should be able to run it without any problems.
I only have a three year old Ryzen 1600 @ 3.4 and a rubbish r9 390 8GB and I get 20 fps and that’s playable. I mean, it’s not perfect, sure.
Have you tried disabling everything “special” like DLSS and bloom etc. and turning them on one by one to see what is causing it?
I also have to say that it’s difficult to know what your issue is, you just say “More FPS and smoother”, so unless you are getting 18fps or lower, you are still doing much better than lots of us :¬)