Bluetooth connection unexpectedly timing out with macOS Sequoia

After the macOS Sequoia update, my app seems to have an issue with Bluetooth communication between macOS and iOS that uses CoreBluetooth for Central-Peripheral communication.

Setup:

  • The iPhone (in my case: iPhone 14 Pro with iOS 18.0 (22A3354)) acts as the Central, and the Mac (in my case: 14" MacBook Pro 2023 with macOS 15.0 (24A335)) as the Peripheral.
  • I’ve implemented a mechanism where the Central (iPhone) sends a message to the Peripheral (Mac) every 15 seconds to keep the connection alive (Because it needs to wait for notify characteristic updates).
  • I never noticed this kind of issue before, but with macOS Sequoia I get it permanently.

Issue:

The connection drops unexpectedly after a period of time (sometimes 20 seconds, sometimes a few minutes) with CBErrorDomain - code 6: The connection has timed out unexpectedly.

Sample Code:

Peripheral (Mac):

Central (iPhone):

Reproduce:

I attached sample code including the Central-Sample (for iPhone) and Peripheral-Sample (for Mac).

  • Just run the Peripheral-Sample (after granting Bluetooth permissions).
  • Then run the Central-Sample and select the Mac device in the list
  • After selecting it should connect, discover the service & characteristic and should start writing messages to it.
  • After some time the func centralManager(_ central: CBCentralManager, didDisconnectPeripheral peripheral: CBPeripheral, error: (any Error)?) {should get called with timed out unexpectedly error.

Could anyone please look into this issue and advise on whether there’s a known bug or any workaround? Any guidance would be greatly appreciated, as this impacts the stability of Bluetooth communication between the devices.

Thanks in advance.

Logs:

I also ran the console.app during this issue which got these errors (if this is helpful):

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Bluetooth connection unexpectedly timing out with macOS Sequoia
 
 
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