I’ll echo what @Kubisuro said. This first public beta release of iOS 13 was based of the second developer beta which is still pretty early in the beta cycle (personally, I don’t usually start using the betas on my devices until around the 4th - 6th developer beta).
What ends up happening, is there’s bugs in some of the UI code provided by Apple (UIKit) because they’re changing lots of things. I’m purely speculating here, but the missing labels could actually be there, but there could be an issue in the beta with how iOS handles colors now (with the new dark mode introduction in iOS 13 a color can be a “light mode color” and a “dark mode color” and have two different values).
The Rachio app hasn’t been built against the iOS 13 SDK so we’re not using any of the new iOS features in the production app, but when iOS 13 release gets closer this fall, we’ll definitely make sure there aren’t any unexpected breakages.
Usually, these kind of issues get fixed up pretty quickly in the iOS beta and then 3rd party apps start just “working” because things have started settling down.