After some Windows 10 upgrade from 1909 to 20H2, we found that DNS was break on these machines. We are not exactly sure what is the percent of this happening but not all.
We notices that our case is exactly same that is described here:
https://docs.microsoft.com/en-us/answers/questions/339492/dns-error-after-windows-10-20h2-upgrade.html
And same fix helps which is described there. We would like to investigate why this happens on some clients and how to prevent it or fix it while upgrading.
Any help would appreciated.