That also happens to be exactly the kind of math error AI is notorious for making. I bet the article was written by AI and likely not even proofread by a human.
Or it wasn't making any kind of claim and just posting what the celebrity claimed and providing estimated revenue from both service based on what she claimed. Why are you falsely blaming this on AI for no reason?
The article didn't contradict itself since it did not make the claim that she made more money from Only Fans, the celebrity did. They just posted the estimated revenue from both services which doesn't match up with what she said. The only conclusions we can come up with is either their estimation is completely off or she was exaggerating her example.