B4R Question Arduino 101 BLE strange behaviour 12v vs USB

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My arduino 101 will connect with BLE when using power from USB, but won't connect using the 12v barrel jack for power.

I've tried the USB power using a wall wart power, BLE connects.

Also it's not freezing on Serial Connect because I've set up a blink to test this. Also removed the serial.initialize.

Any ideas? Maybe I need to run the board with USB power instead of the 12v jack!!