Hi Apple developer experts, I am getting one critical issue related to Bluetooth on MacOS 12.0.1 and MacOS 12.1. Since we upgrade to MacOS 12.0.1 the bluetooth not working to the pair with device anymore with detail checking as below: The issue was not happened from MacOS 10.7 to 11.3 Big Sur. Only happened from macOS Monterey 12.0.1 + I got the console log with these message: [CoreBluetooth] No name or address and [CoreBluetooth] WARNING: Unknown error: 431. Sometime I also got this: [CoreBluetooth] WARNING: Unknown error: 10702 Checking with tool PacketLogger I saw the error message in HCI Event : Authentication Complete - PIN Or Key Missing and Command Complete [FD4E] - LE Update Extended Advertising Instance - Invalid HCI Command Parameters The code get IOBluetooth Local Services in macOS Catalina response the channel id is 2 or 3 for the hardware device depending on. While in macOS Monterey is response with channel id 1. (The valid RFComm channel from 1 to 30 - IOBluetooth library) The RFCOMMChannel in macOS Monterey is not opened and not response the notification. Everything works fine with older MacOS (I used PacketLogger to check). This maybe the main issue that the Pair device is not working anymore. Note that the status BT connected just keep around 5 seconds then disconnected. My code request RFCOMM include service name, L2Cap attribute, RFComm attributes, SDP attributes with uuid I am very appreciate If anyone knows what should be changed or fix. Many thanks. I tried a lot of cases but it still not working, include reset the bluetooth from my Mac machine. Our customer complaints a lot since they updated macOS Monterey and the bluetooth has been not working properly. Any help would be greatly appreciated. Thank you!