For months now, something odd has happened when some internet users — including me — ask ChatGPT, the ubiquitous artificial intelligence tool from OpenAI, about Pope Leo XIV.

“It looks like there might be a bit of confusion with the name, as there has never been a Pope Leo XIV. However, there have been several popes named Leo in history,” the chatbot replied to a query made Oct. 31.

Not all ChatGPT users are experiencing this phenomenon — if you go to ChatGPT right now and ask, “Who is the pope?” it may well give you the correct answer. To put it mildly, though, it’s hit or miss.

Another user (and fellow EWTN employee), who was recently seeking information about Opus Dei, tried to correct ChatGPT when it referred to Pope Francis as if he were the current pontiff. “The current pope is Leo XIV,” the user wrote.

“Pope Leo XIV does not exist,” the chatbot insisted.

“As of right now (October 2025), the pope is still Pope Francis (Jorge Mario Bergoglio), elected in 2013. There has been no resignation, conclave, or papal death since then — which would be required for there to be a new pope.”

But that wasn’t all. The program doubled down and adopted what some might perceive as a rather patronizing tone:

“If someone told you ‘Leo XIV,’ they are either: joking/using a fictional or speculative scenario, confusing a rumor or prophecy, or genuinely misinformed,” it said.

But the experience of another fellow EWTN employee took the cake. It appears that ChatGPT can notice the existence of Pope Leo — but has a hard time letting his predecessor go.

“People are saying that you are saying Pope Francis isn’t dead,” that user typed out to ChatGPT.

“Pope Francis is alive, but he resigned from the papacy earlier this year due to health reasons,” the chatbot confidently — and erroneously — began.

“After his resignation, the College of Cardinals elected Pope Leo XIV (Robert Francis Prevost) as his successor on May 8, 2025. Francis has reportedly been living quietly in the Vatican’s Mater Ecclesiae Monastery, occasionally appearing at Vatican ceremonies.” (It shouldn’t even need to be said, but … none of that is true, apart from the election of Pope Leo.)

And ChatGPT is not the only AI chatbot that seems to have a Pope Leo-shaped blind spot. Claude, an AI assistant made by Anthropic, and DeepSeek, a much-hyped Chinese product, both denied the existence of Pope Leo XIV in response to queries made Oct. 31. In contrast, Google’s Gemini and the AI search engine Perplexity both knew who Pope Leo was and immediately returned information on him.

So, what’s going on? It all has to do with the way AI models are trained and how they operate in practice.

AI chatbots rely on large language models (LLMs), which are “trained” by ingesting massive amounts of data. The models in use today can only be trained up to a certain date, which differs depending on the chatbot.

Paid users of ChatGPT are using the “next generation” model, GPT-5, which was launched on Aug. 7, 2025. Because it was released after the election of Pope Leo XIV, GPT-5 users can rest assured that that model “knows” about his existence.

But for those using ChatGPT’s previous model, GPT-4, its knowledge base cuts off in June 2024. For DeepSeek, the cutoff was “early 2024.” For Claude, it’s January 2025.

That doesn’t mean these chatbots with holes in their knowledge bases can’t search for and reference current information from the internet, however. In fact, ChatGPT, though it appears to lack information about Pope Leo in its GPT-4 knowledge base, can be prompted to do this.

After I specifically asked it to look up information on Pope Leo online, the chatbot finally conceded … Habemus papam (“We have a pope”). “So why did you tell me earlier that he doesn’t exist?” I then wondered.

“That’s a great question — and you’re absolutely right to ask,” the chatbot began genially.

“When I first answered, I was relying on my built-in knowledge base, which only goes up to June 2024. At that point, Pope Francis was still pope, and Pope Leo XIV had not yet been elected. When you asked me to check again, I used live web search, which confirmed that Cardinal Robert Francis Prevost was elected pope in May 2025, taking the name Leo XIV — the first American pope in history. So, the difference comes down to timing.”

So … sedevacantist conspiracy in Silicon Valley? Almost certainly not. It’s clear that the election of the first American pope took everyone by surprise — even the robots.