I would suspect a bad hall sensor or connection to the hall sensors. Check the connections first. Make sure the pins are fully inserted in the body.
You can test the hall sensors by using a voltmeter and turning the wheel slowly backward. With the controller on, but no throttle, you can measure the voltage on each hall signal wire. You should see each one alternate 5v on/off as you slowly turn the wheel. Best to measure at the controller to test all the connections between.
You could also have a bad connection on a phase wire or some kind of failure in the controller.
I wish we knew what the blinking codes for the LED are.
"One test is worth a thousand opinions"