Could be pure coincidence, but my Claude Code session last night was an absolute nightmare. It kept forgetting things it had done earlier in the session and why it had done them, messed up a git merge so badly that it lost the CLAUDE.md file along with a lot of other stuff, and then started running commands on the host machine instead of inside the container because it no longer had a CLAUDE.md to tell it not to. Last night was the first time I've ever sworn at it.
I think this is just the nature of a nondeterministic system; occasionally you're gonna be unlucky enough to encounter the leftmost segment of the bell curve.
In my experience dumping a summary + starting a fresh session helps in these cases.