Hub locks up backing up.

#1
Got home from a ride plug the bike up to charge it afterwards I went to push it backwards and it felt like the motor was locked up. However you can push it forward pedal it and even use the throttle everything seems fine Ford. It's always been very easy to push backwards. Like I said now it feels like the motors locking up trying to go backwards. Any ideas, rear hub 750w 48v thanks.
 

Electric Bike Shops Near You