Hello,
We develop Barra, an order-ahead pickup app in Saudi Arabia built to support productive families: small home-based businesses, mostly women cooking or making handmade products from home. Customers order from them in our app and collect the order from their car.
The families depend on one notification: when a customer places an order, the family's iPhone receives a "New order" push with our own sound. They have a few minutes to accept it before it is cancelled automatically, so hearing that sound is how they earn their income.
The problem: families report that this notification sometimes plays its sound and sometimes arrives silently — same iPhone, same settings, ring/silent switch off. Our server logs show every push is sent and accepted by APNs (via Firebase Cloud Messaging) and the notification itself appears. Only the sound is sometimes missing.
We are not trying to bypass the silent switch and we are not asking for Critical Alerts. If a family puts the phone on silent, we respect that. The sound only goes to merchant devices, only for a real customer order (plus at most one reminder per minute while the order is still waiting).
Our setup
Headers: apns-push-type: alert, apns-priority: 10, an apns-collapse-id per order
aps: alert {title, body}, sound: "bra_order_alert.caf", badge: 1, interruption-level: "time-sensitive"
bra_order_alert.caf: IMA4, 44.1 kHz, 16.4 s, in the main bundle
Foreground: willPresent returns banner + badge + sound
Our next build adds the Time Sensitive Notifications entitlement (it was missing before)
iPhones on iOS 18.x, 26.x and 27.0
Questions
Which conditions can make iOS deliver an alert push silently while the silent switch is off? For example notification summary, Focus, several notifications close together, Apple Watch or Bluetooth audio routing, replacing a notification with the same apns-collapse-id, the sound file's length or format, or the app's own audio session.
Is there anything in our payload or sound file that could make the sound play only some of the time?
When a notification replaces an earlier one with the same apns-collapse-id, does iOS play the sound again?
What do you recommend for merchant apps so order notifications are reliably audible, while fully respecting the silent switch?
Filed as FB25199572. Thank you!