HMHome addAndSetupAccessoriesWithCompletionHandler: issue

On iOS 13 Beta attempting to add a HomeKit accessory with HMHome addAndSetupAccessoriesWithCompletionHandler: instantly fails if the accessory is not on the network.

After scanning the input code with the camera the HomeKit control displays the "Add Accessory to Network?" alert and while the alert is in the foreground the UI beneath it changes to "Couldn't add Accessory".

However if the user selects "Allow" the accessory does get added to the network but at that point HomeKit has given up on pairing.

Has anyone else run into this?