Severely diminished performance following Usage Policy warning. Claude is now silently underperforming on every task-- what's going on?

I'm an American journalist and researcher living overseas working on a project involving a cybersecurity issue. I've been using Claude Cowork (Max 20x plan) to compile information. A few days ago out of the blue, I got an error entitled, "It looks like a few of your recent prompts don't meet our Usage Policy," after attempting to use Claude to summarize information posted by a ransomware group. I did not ask Claude to perform any sort of malicious action-- I literally gave it a list of ransomware victims an