Server update to 0.4.0.1 - I am locked out of my server

Hello. I just updated my server on Start9´s recommendation https://x.com/start9labs/status/2085811035735556465?s=20.

Now I have no access. What do I do?

It resolved after unplugging my backup SSD. Still strange and unnerving. Backing up the new OS and hoping for the best.