Illustration by Tag Hartman-Simkins / Futurism. Source: Jerod Harris / Getty Images for Netflix Rumors are running rampant online that Matt and Ross Duffer used OpenAI’s ChatGPT when producing the last season of “Stranger Things” after fans zoomed on a still from a behind-the-scenes documentary that appears to show that one of the brothers had the AI chatbot open while working on the script. “WTF man, now we know why season 5 sucked,” wrote one upset fan o