Panera Bread’s digital channels have been knocked down by an unexplained outage that began over the weekend.

The fast-casual chain’s website and app have been down since Saturday morning, which was first reported by the Silicon Valley Daily. Stores are open, but only for ordering at the register. Even kiosks in units were down and remained out of action on Monday.

The chain’s website says, “We’re working on it. Ovens are warm, bread is baked and our team is ready to serve you in our bakery cafes.” The app says the brand is conducting “essential system maintenance and enhancements.”

Company officials, however, did not respond to questions about the outage, and workers in units say they have been given no explanation.

At the register, guests who said they are members of the Unlimited Sip Club, the chain’s subscription program, were handed cups for free drinks, but workers had no way to check subscriptions or access the loyalty program.

Reddit posts indicate the outage has impacted catering and gift cards, as well. But it appeared third-party delivery orders were still coming in to units.

Some workers on Reddit question why the stores remained open, saying there hasn’t been “a single peep from corporate on when we are getting a fix.” Some have speculated, without evidence, that a cyberattack is to blame.

The outage comes as the chain prepares for what the company has described as the biggest menu transformation in its history.

The “new era” menu is not expected to launch until April 4, but some units in California were closing early Monday for staff training in preparation for the rollout.

System outages are becoming a more regular occurrence in chain restaurants with the growing reliance on digital channels.

Earlier this month, McDonald’s was hit with a technology outage that impacted some global markets outside the U.S. The problem was blamed on a third-party provider’s configuration change.

Golden Corral suffered a data breach earlier this year. Last year, roughly 300 Yum Brand units in the U.K. had to close temporarily following a ransomware attack. And both Wendy’s and Five Guys have been targeted with class-action lawsuits following data breach incidents in recent years.

UPDATE: As of Tuesday morning, Panera Bread’s website was back up and the app was offering partial services, but it appeared the loyalty program was still not functioning. The company has not offered any explanation for the outage.

Source restaurantbusinessonline.com