AI owner Elon Musk made some big claims about Grok’s capability, saying it was “better than PhD level in every subject.”

Hours later, on Wednesday, X CEO Linda Yaccarino resigned from the company after just two years at the helm, though it wasn’t immediately clear whether her departure was related to the Grok issue.

Two days before the launch of Grok 4, the previous version of the chatbot made headlines for praising Adolf Hitler in response to an antisemitic question posted by a user on X (formerly Twitter).