Open Radar

 
Summary:
Our app uses iPhone in BLE Central role and connects to a remote device (an Android 5+ device) in Peripheral role.
Our code works great on every combination of iOS 8.1 - 10.0.2 and iPhone 4S - 6S that we have tried, but fails with the iPhone 7 and 7+. 

After successfully discovering, connecting to the peripheral and retaining a reference to it, we call -discoverServices on the CBPeripheral, but the corresponding CBPeripheralDelegate didDiscoverServices method is never called (yes i triple checked the delegate property is set 😇)… eventually after 30sec the didDisconnect delegate method is called with error 0 "Unknown Error". 

The specific hardware combination that fails is:
iPhone 7 iOS 10.0, 10.0.1, 10.0.2 and iPhone7+ 10.0.1 in Central role. Connecting to any Android device in Peripheral mode, except the Samsung S6 Edge.

We have tested:
iPhone 4S, 5, 5S, 6, 6+, 6S with various versions of iOS from 8.1 through 10.0.2, and these have all happily connected to a wide variety of Android 5.0+ devices.

We typically call -discoverServices with our expected ServiceUUID. I have tried setting this to nil, but it made no difference. I have tried checking before calling discoverServices if the .services property on the CBPeripheral is already populated… it's not.

I have raised the issue in the developer forums:
https://forums.developer.apple.com/thread/63815

I believe this report is a duplicate of:
rdar://28479978
https://openradar.appspot.com/28479978

Steps to Reproduce:
In code:

import CoreBluetooth
1. CBCentralManager -scanForPeripheralsWithServices:nil options:nil
2. wait for delegate -centralManager:didDiscoverPeripheral: to be called, retain the CBPeripheral
3. -connectPeripheral:options:
4. wait for delegate -didConnectPeripheral: to be called
5. -discoverServices:
6. …

Expected Results:
Delegate method -didDiscoverServices: should be called with the discovered services.

Actual Results:
With the combination of iPhone 7 and 7+ and any Android device we tested except the Samsung S6 Edge, -didDiscoverServices: is never called.
Rather delegate method -didDisconnectPeripheral:error: gets called after 30sec with Error 0 Unknown Error.

On any other iPhone I've tried, down to a iPhone 4S, -didDiscoverServices: is called promptly.

Version:
iPhone 7, 10.0.0, 10.0.1, 10.0.2. iPhone 7+ 10.0.1. Xcode 7.3.1, Swift 2.2, OSX 10.11.6

Notes:
Android devices we have tested in Peripheral role:
Samsung Galaxy S7 Android 6.0.1
Samsung Note 4 Android 6.0.1
Cyanogen OnePlus One Android 6.0.1
LG G5 Android 6.0.1
Sony Xperia Z1 Android 5.0.2
Samsung Galaxy S5 Android 5.0
Nexus 6 Android 6.0.1
Samsung S6 Edge

Configuration:
iPhone 7 and 7+ purchased in Sweden, unlocked.

Attachments: