I didn´1 have this problem with AMD Ryzen 9 5900x and Quadro P5000 but as I have the general problem of a slow GUI regarding SME and Render setup window Lele (Senior member) wrote in a post , that you should manage your threads so that the first core is only reserved for 3dsMAX. Yesterday I found, that the the monitor management software DisplayFusion also is a cause for slugishness of MAX´s dialog windows. Do you use it by chance? I have two other problems with the VFB- If I do IPR there and hit render MAX sometimes doesnt react anymore. The other thing is that during IPR is running the AutoBack feature of MAX doesn´t work.
Just now Ifound an article regarding that topic in the Autodesk forum which I didn´t know so far:
https://knowledge.autodesk.com/support/3ds-max/troubleshooting/caas/sfdcarticles/sfdcarticles/3ds-Max-UI-lags-or-seems-sluggish-even-on-very-fast-multi-core-CPUs.html