iOS 26 Bluetooth repeatedly sends connection parameter updates

Question

Created 3w

Replies 2

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Participants 2

When my Bluetooth peripheral device has both HID and MIDI services, the iOS Bluetooth host repeatedly sends different "Control Opcode: LL_CONNECTION_UPDATE_IND" to the peripheral, updating approximately every 100ms.

The Bluetooth peripheral cannot handle such high-frequency update requests and typically disconnects with an error 0x28. My Bluetooth device uses the NRF52832 chip, and I have communicated with NORDIC and replicated this issue.

This problem only occurs on iOS 26; it does not happen on earlier versions. I think it might be caused by the HID service in iOS requesting faster connection parameters for low latency, which then gets erroneously reverted for an unknown reason, leading to repeated competition and entering into a deadlock.

Here is the communication record with NORDIC: https://devzone.nordicsemi.com/f/nordic-q-a/124994/ios-26-bluetooth-disconnect-issues

This is the screenshot captured using the Bluetooth sniffer:

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Answer 1

Engineer OP

Apple

2w

This is something we will need some diagnostics to investigate.

Please file a Bug Report on this

In your bug report we would need some diagnostics logs as well. Please go to https://developer.apple.com/bug-reporting/profiles-and-logs/ and follow the instructions for Bluetooth for iOS to install a logging profile on your device.

Then reproduce the issue, and follow the instructions at the above link to create a sysdiagnose.

And attach that to the bug report as well.

If you have separate sniffer logs that shows the interaction, also do include those. Along with the logs/screenshots you have included here.

We would also like to know the peripheral devices you are seeing this issue with. Make/Model and if you know, the BT chipset details (HW/FW versions and manufacturer) would be helpful to track this down.

Once done, please share the Feedback ID here, and @mention me in your response so we can take a look at this right away.

Argun Tekant /  WWDR Engineering / Core Technologies

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Answer 2

Junhao_XSONIC OP

2w

Also, this is a screenshot from the iPhone log file at \logs\Bluetooth\bluetoothd-hci-latest.pklg. It shows the repeatedly connection parameter updates.

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