My 2 attempts at updating 18932 to 18936, one with WS enable and the other with WS disable, WU reset and clean boot failed. A 3rd attempt at updating from ISO failed and a 4th attempt at a clean install from within 18932 also failed.
I decided to restore an image of 18922 and try one more time but unfortunately it was corrupted so I had to download a new ISO from UUP dump. After a clean installation, the update from 18922 was a success which suggests that...
18936 has a bug updating from 18932 but not from a previous build (not applicable if done in VM)
7/20 UPDATE: based on new findings, the failures must be the result of changes made to build 18936 which carried over to 18941 causing the SATA ACHI driver to fail initialization during BOOT operation (not applicable if done in VM)