comical videos of the tech making mistakes were viewed millions of times. In one clip, a customer seemingly crashed the system by ordering 18,000 water cups, while in another a person got increasingly angry as the AI repeatedly asked him to add more drinks to his order.

Since 2023, the fast-food chain has introduced the technology at over 500 locations in the US, with the aim of reducing mistakes and speeding up orders. But the AI seems to have served up the complete opposite. Taco Bell's Chief Digital and Technology Officer Dane Mathews told The Wall Street Journal that deploying the voice AI has had its challenges.

"Sometimes it lets me down, but sometimes it really surprises me," he said. He said the firm was "learning a lot" - but he would now think carefully about where to use AI going forwards, including not using it at drive-throughs. In particular, Mr Matthews said, there are times when humans are better placed to take orders, especially when the restaurants get busy. "We'll help coach teams on when to use voice AI and when it's better to monitor or step in," he said.

The issues have been building online as disgruntled customers take to social media to complain about the service - with many pointing out glitches and issues. One clip on Instagram, which has been viewed over 21.5 million times, shows a man ordering "a large Mountain Dew" and the AI voice continually replying "and what will you drink with that?". It isn't the first time there has been issues with AI not getting it right when it comes to processing food and drink orders.

Last year McDonald's withdrew AI from its own drive-throughs as the tech misinterpreted customer orders - resulting in one person getting bacon added to their ice cream in error, and another having hundreds of dollars worth of chicken nuggets mistakenly added to their order. But despite some of the viral glitches facing Taco Bell, it says two million orders have been successfully processed using the voice AI since its introduction. (BBC/ Getty Images)