Why is my iOS wired or Bluetooth accessory not working correctly anymore?
iOS 12.4+ users may experience longer than usual delays when trying to use accessories with Zello in the background. It may take from 2-7 seconds for recording to begin. Wired accessories will generally be faster, from 2-5 seconds; Bluetooth accessories will be slowest, from 5-7 seconds.
This behavior is the result of a workaround for a bug which was introduced by Apple in iOS 12.4+. The bug effectively prevents voice apps from recording in the background. Apple has acknowledged this is an issue on their side and are working on a fix; however, there is no firm date on when it will be available.
Unfortunately, we are not able to avoid or reduce the startup delay. In the meantime, we recommend using wired accessories or keeping Zello in the foreground.