Here is my journey with the Repair and Validation tool on 10.8.1.
In the attached file you'll see the time it took to remove the patches and how long it took before it failed to remove some patches.
Although it's not logged (probably because of the reboots), but the first five runs did end with the successful removal of the last patch mentioned.
At every run, except the first, it failed to remove some patches.
After run 6 the tool exited with the message that all defective patches were removed and I could update the system again. But after starting the tool again, the tool said the defective patch "ArcGIS Enterprise Sites Security Patch A" is installed, although it isn't. The tool still shows the three patches that could not be removed:
Portal for ArcGIS Security 2022 Update 2 Patch
Portal for ArcGIS QuickCapture Security Patch
Portal for ArcGIS 10.8.1 ArcGIS Workforce General Patch B
During run 7 the ArcGIS QuickCapture patch was removed (it failed to be removed every other time I ran the tool). The other two patches failed to be removed.
During run 8 there were just two patches left, but they kept failing to be removed.
In a different logfile than the one indicated by Esri, I saw this message:
Error 1706. No valid source could be found for product Portal for ArcGIS 10.8.1. The Windows Installer cannot continue.
So I think I'll wait for more info on this from Esri Support.
I want to upgrade to 10.9.1, but I'm not sure if that is a possibility now that I have two patches that apparently can't be removed.