In the nearly three years since McDonald’s announced that it was partnering with IBM to develop a drive-through order taker powered by artificial intelligence, videos popped up on social media showing confused and frustrated customers trying to correct comically inaccurate meals.

“Stop! Stop! Stop!” two friends screamed with humorous anguish on a TikTok video as an A.I. drive-through misunderstands their order, tallying up 240, 250 and then 260 Chicken McNuggets.

In other videos, the A.I. rings up a customer for nine iced teas instead of one, fails to explain why a customer could not order Mountain Dew and thought another wanted to add bacon to his ice cream.

So when McDonald’s announced in a June 13 internal email, obtained by the trade publication Restaurant Business, that it was ending its partnership with IBM and shutting down its A.I. tests at more than 100 U.S. drive-throughs, customers who had interacted with the service were probably not shocked.

The decision to abandon the IBM deal comes as many other businesses, including its competitors, are investing in A.I. But it exemplifies some of the challenges companies are facing as they jockey to unlock the revolutionary technology’s potential.

Other fast-food companies have had success with A.I. ordering. Last year, Wendy’s formed a partnership with Google Cloud to build out its A.I. drive-through system. Carl’s Jr. and Taco John’s have hired Presto, a voice A.I. firm for restaurants. Panda Express has approximately 30 automated order takers at its windows through a partnership with the voice A.I. firm SoundHound AI.