If you disconnected and re-connected wiring, it might be that the stepper for the extruder isn’t wired the same. There’s a step in the 3d printer setup guide that talks about motor wiring and it might be helpful to double check.
If you’re sure it didn’t change ('cause you didn’t move the wiring) then ignore this.
ahh, a developement, the motor works correctly else where on the board, and now the exstruder port just loadly clats about a tooth clock wise then a tooth anticlockwise, jigging to and fro…