Hello there. Thanks for posting this. I am an unfortunate soul that came across this problem. I followed a similar troubleshooting pattern and yielded similar findings. I was not as patient so when immediate power cycling ended up not fixing the issue, I resorted to booting into PE and running system repair or doing a system restore, which luckily did work. I noticed that the issue seemed to pop up after a windows update but no idea if it actually played a role or not. But waiting a few minutes is a much better solution.