Device and software:
- iPhone model: iPhone 15 Pro
- iOS 27 Public Beta 6
- Build: 24A5430a
- BLE receivers: two independent ESP32's
- IRK has worked reliably on iOS 26 and past versions.
Observed behavior:
- With the iPhone display on both BLE receivers detect advertisements that resolve correctly using the enrolled IRK.
- No more than 10 seconds after the display is turned off, the IRK-resolvable advertisements stop.
- The IRK identity returns immediately when a notification wakes the display or when I manually do.
- Bluetooth itself remains active while this happens. The receivers continue to see several strong advertisements from the phone with some unidentified rotating addresses.
- The unidentified addresses rotate periodically and cannot be associated with the enrolled IRK.
Additional observations:
- When my Apple Watch is powered on and connected, the iPhone remains IRK-detectable while the screen is off. It stops again when watch is disconnected.
- Connecting Bluetooth headphones does not have the same effect. The IRK-resolvable advertisement stops even while music continues playing.
- Moving the affected phone between two receivers confirmed that the unidentified rotating advertisements physically followed the phone.
- The existing IRK remains valid because it resolves the phone again immediately whenever the display wakes.
I couldnt find any intentional IRK, private-address or screen-off advertising change documented in the iOS 27 release notes or any discussions online.
Has anyone else observed this on iOS 27?