Try replacing some of the built in extensions with the ones from https://extensions.gnome.org/
e.g. "AppIndicator and KStatusNotifierItem Support" from the repos seemed to break for me a couple of weeks ago. I also tried Dash to Dock (I think) from the repository and at some point couldn't boot after some updates. I don't know if it was the problem though. It may have been just coincidence when I rolled back the update I rolled back to before I installed it and everything was okay when I tried to update again.