Repeated connection interval updates on iOS 26

[nrbrook]

We have noticed an issue with our device built on nRF5 SDK + nRF52832 when connected to iOS 26.

Initially after connection, everything is ok. Then we attempt a connection parameters update. After this update, seemingly regardless of the parameters, iOS 26 gets stuck in a loop switching between 7.5ms and 15ms intervals. I have monitored the connection with PacketSniffer, and can't see any further requests after our initial request. I've attached the packet log. I've tried connection interval ranges of 7.5-15ms, 11.25-15ms and 15-15ms, all have the same effect. Also when the connection interval is later changed to 50-75ms, the updates continue.

This seems like an iOS bug and I will report it to Apple, but I wondered if Nordic might have any insight?

Packet log attached.

packetlog.pklg

[HarryGe]

Hello nrbrook,
I have the same problem, iOS 26 keeps sending me connection parameter updates until I get an error saying Reason: 0x28 disconnected.
Then it automatically reconnects and disconnects again in a loop.
I'd like to know how you solved this problem, thank you very much.

[HarryGe]

Are you using the Bluetooth MIDI service?   I found that as long as I turn off this service, the system will be normal.