This article originally appeared at The Takeout.

Many fast food restaurants have been experimenting with artificial intelligence in recent months, trying to figure out how best to use the evolving technology to drive sales and increase efficiency. Many restaurant chains have tested AI-assisted drive-thru lanes, but the recent struggles of one AI company illustrate the potential shortcomings of this model.

Presto Automation supplies AI solutions, specifically voice recognition technology, to a number of major fast food chains including Checkers and Rally’s, Del Taco, and both Carl’s Jr. and Hardee’s. Presto’s voice bots are in use across 145 Hardee’s, Carl’s Jr., and Wienerschnitzel restaurants as of February 1, 2024. Restaurant Business reports that the company also supplies digital ordering tablets to casual restaurant chains such as Applebee’s, Chili’s, and Red Lobster.

However, Presto has recently struggled to appease investors; the company is running out of money and has to figure out how to pay its lenders $6 million this month. To make matters worse, Presto is losing some of its biggest clients.

Del Taco began using Presto’s voice AI in its drive-thru lanes in 2022 and in early 2023 said the technology was “exceeding expectations.” Del Taco made plans to expand its use of the tech across more of its 600 restaurant locations, Restaurant Business reported at the time. Now, however, Del Taco has made the decision to stop using the technology at its restaurants.

Presto’s technology does use AI voice recognition to take down orders in the drive-thru lane, but a significant portion of the process still requires an actual employee’s involvement as well. The bot takes down the order from the customer, but it is still the responsibility of the employees to input the order and ensure its accuracy. The voice assistant technology has gone through multiple iterations, but even its most advanced version is still only completing 30% of orders without the help of a human being.

Other chains such as White Castle and McDonald’s have also tested out AI voice recognition in their drive-thru lanes. However, from the customer perspective these new technologies have been a mixed bag. When McDonald’s first tried out similar tech in one of its drive-thru lanes, internet users roasted the bots online for misinterpreting their orders.

Presto’s AI-powered voice recognition has been the company’s flagship offering since its inception—but even its ordering tablets have apparently failed to impress in the long term. Applebee’s, Chili’s, and Red Lobster have all confirmed they will not be renewing their contracts with Presto.

Presto’s leadership nevertheless appears to be optimistic about the future. “We are experiencing significant interest from franchise operators today who are interested in talking to us about Voice AI,” said Presto CEO Xavier Casanova in a November 2023 press release. “We look forward to generating widespread adoption of our Presto Voice AI solution across North America as brands and franchisees adapt to this new reality.”