I have problems with drivers above 9599 not in random noises, but in the absence of first 1 second of sound when starting any playback from an audio device. I.e., as if the device goes to sleep and does not have time to wake up when starting playback. Spdif connection. 9616, 9621 - it does not matter... Therefore, I also stay at 9599.
You just encountered one of 2 problems that made me stop using Realtek HDA driver and never look back motivating me to start Realtek UAD generic project. The other problem I saw in alternate was UI loading but missing equalizer.
Lately i learned how to uninstall previous driver and install latest. Turn of net, unistall driver using DDU and then install new driver. Even then sometimes new driver fail to load. Just now found on web search that m$ pre-installed driver interfere with realtek latest driver and stop working totally. There was no such problem with HDA 6.0.9205 version. Just installed it and working FINE. Relieved me from finding new UAD and UI everytime.