Whether you order a ride in the Lyft or Uber app, the car that arrives will often have stickers for both ride-hailing companies. The same drivers may also juggle gigs for delivery services like Postmates, DoorDash, or Instacart. About 48% of drivers are signed up with two gig services, and about another 18% are with three of them, according to a 2018 survey by The Rideshare Guy, a news site and driver consultancy service.

That’s where a company called Driver Partners saw an opportunity. Its Android app, Mystro, hooks into the Lyft, Uber, and Postmates apps to help drivers evaluate offers and automatically switch between the services.

But Mystro abruptly stopped working with the Lyft app in March, says Driver Partners, and the two companies disagree on why. Dwayne Shaw, cofounder and co-CEO of San Francisco-based Driver Partners, claims that Lyft deliberately altered its app on March 12 to break the connection. (Lyft has not responded to that assertion.) A week later, Driver Partners issued an app fix to restore the connection, says Shaw. And then it stopped working again.

The cycle has repeated itself five times, Shaw claims, with the latest broken connection occurring on May 22 and the latest fix on June 8.

Since the Lyft disruptions began in March, Mystro’s number of paying subscribers has dropped from around 10,000 to 7,000, says Shaw. Meanwhile, he says connections to Uber and Postmates have remained functional the whole time. (Uber did not return multiple inquiries and a Postmates spokesperson declined to comment.)

“It’s probably the most popular app out there with drivers [because] it lets you drive for both Uber and Lyft automatically and makes driving a lot safer,” says Harry Campbell, founder of The Rideshare Guy, and an adviser to and stockholder in Driver Partners.

Why is Mystro only available on Android? It takes advantage of the operating system’s “accessibility service,” which allows developers to create an alternative interface into an app. Apple’s iOS doesn’t have this functionality.