[Bug] SPIKE Hub Bluetooth fails on M1 Mac with macOS 26.3 – GATT Server disconnected in both Pybricks Code App and Web

[MaYongfei123]

I am experiencing a Bluetooth connection issue with a LEGO SPIKE Hub on an M1 MacBook Pro running macOS 26.3.

The same SPIKE Hub connects successfully to Pybricks via Bluetooth on a Windows computer. However, on my MacBook Pro, Bluetooth connection fails in both the Pybricks Code desktop app and the web version.

The Hub can be discovered via Bluetooth, but during the connection process Pybricks loses the GATT connection and reports the following error:

Failed to execute 'getPrimaryService' on 'BluetoothRemoteGATTServer': GATT Server is disconnected. Cannot retrieve services. (Re)connect first with device.gatt.connect.

Full error:

NetworkError: Failed to execute 'getPrimaryService' on 'BluetoothRemoteGATTServer': GATT Server is disconnected. Cannot retrieve services. (Re)connect first with device.gatt.connect.

Environment

• Hub: LEGO SPIKE Hub
• Computer: MacBook Pro
• Chip: Apple M1
• OS: macOS 26.3
• Pybricks Code desktop app: Connection fails
• Pybricks Code web version: Connection fails
• Connection method: Bluetooth
• Same SPIKE Hub on Windows: Works normally

Steps to reproduce

1. Turn on the SPIKE Hub.
2. Open Pybricks Code on the M1 MacBook Pro.
3. Click the Bluetooth button.
4. Select the SPIKE Hub.
5. Attempt to connect.
6. The connection fails/disconnects and the GATT Server error appears.

I have tested both the desktop application and the web version of Pybricks Code on the Mac, and both have the same problem.

The exact same SPIKE Hub works correctly via Bluetooth with Pybricks on Windows.

This makes me suspect that the issue may be related to Bluetooth/GATT handling on macOS 26.3 or Apple Silicon rather than the SPIKE Hub itself.

I have attached a screenshot of the error message.

Please let me know if there are any additional logs, Bluetooth diagnostics, or other information I can provide to help investigate this issue.[

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[dlech]

Do you have other Bluetooth devices connected at the same time? We have had users report that disconnecting them helps.

If that doesn't fix it, we will need to get a Bluetooth packet capture to see what is going on. See https://bleak.readthedocs.io/en/latest/troubleshooting.html#macos for instructions on how to do that.

I have tested both the desktop application and the web version of Pybricks Code on the Mac, and both have the same problem.

FYI, the only difference is how it looks (having an address bar or not). Both are still the web browser. So no need to try both - they are the same.

[MaYongfei123]

Thank you! Disconnecting the other Bluetooth devices actually fixed the problem.

After disconnecting the other Bluetooth devices from my Mac, the SPIKE Prime Hub connects to Pybricks Code normally and the Bluetooth LED stays connected.

So this does appear to be related to having other Bluetooth devices connected at the same time.

I will try reconnecting the Bluetooth devices one by one to see if I can identify whether a specific device triggers the issue.

[MaYongfei123]

The Bluetooth mouse is a Logitech G603.

I tested it again and the behavior is reproducible:

• Logitech G603 disconnected → SPIKE Prime connects normally.
• Logitech G603 connected via Bluetooth → SPIKE Prime fails to connect and Pybricks Code shows the GATT Server disconnected error.
• My Bluetooth keyboard does not cause the problem.

So the Logitech G603 Bluetooth connection appears to be the specific trigger in my setup.

I also noticed that the G603 appears in the PacketLogger capture. If helpful, I can provide two comparison captures: one with the G603 connected (SPIKE fails) and one with the G603 disconnected (SPIKE works).

[dlech]

Sure. I don't know that we could fix anything from that info, but it would be interesting to see what the difference is nonetheless.