The go to sleep issue is common and has nothing to do with your setup. I suspect it's because for the agent to predict the End of Response token, its response needs some kind of closing, and the most final kind of closing is something like "get some rest".

Oh cool, I thought I had wound up leaving something weird in my CLAUDE.md file that it was always saying Good Night.

I also had this behaviour sometimes, it’s specifically called out in the system card in section 6.2.1.1 - although I didn’t actually see if they said they decisively fixed the issue.