The cutter does not spring back;
The cutter position detection sensor is faulty;
The magnet on the cutter may be missing.
The cutter gets jammed and does not spring back when cutting filament;
The cutter detection sensor is faulty;
The magnet on the cutter is missing.
Check whether the cutter has fully sprung back into position;
Perform cutter calibration to determine whether the cutter sensor is faulty;
Pull open the cutter and check whether the magnet is missing.