I have a HP envy x360 notebook with the Conexant audio ISST drivers. Since 1909 updates expires in about a month, I decided to try what I read previously. I still get the block on windows update. I used device manager to disable the Conexant audio drivers. I did not delete the drivers. I did not reboot since that would have reinstalled the audio drivers. Went to the windows web site used the update for 2020 H2. It installed without any problems. (It took a very long time for the installation to complete). Following installation I checked device manager, the Conexant audio drivers had been reinstalled and everything worked fine. No audio problems or other problems. I used windows update to install the 2021 updates to win 10 2020 H2.
PS: I made a complete backup of my 1909 installation before starting just in case major problems should occur. Didn't need it.
Thank you very much, Jon,
I exactly followed your recommendations and after a long update-process I got the latest Windows version 2020 H2 on my ASUS Zenbook. It worked great and the Conexant drivers are working fine.
PS.: Of course I have also made a complete backup (without needing it).