Just to let you know you are not the only one.
Both my machines boot to the login prompt since the latest updates.
Looks like an issue with sddm (the graphical login manager).
I think I heard they transitioned to Plasma Login Manager but not sure.
I managed to get one of my machines working by reinstalling sddm but I cant get the other one to work trying to do the same things, maybe I remembered the process wrong.
Also theres issues with kwallet. Looks like something broke as it lose all my wifi passwords, VPN keys you name it. Also ssh agent isnt working, possibly connected.
I’m a really big fan of Neon but unfortunately this is the worst update I’ve had in a long while.