The video looks halfway normal there are more than one magnet in the flywheel there for each one will create a flux across the winding.
And depending on the rotation of the motor the magnets can be reversed in there mounting to the flywheel.
Remove the flywheel and drag a small magnet over the flywheel magnet if you have cracks in the magnetic material in your flywheel that will create additional flux peaks in the flywheel that are much weaker due to the smaller pieces of magnet I suspect you dropped your flywheel and cracked the magnets (edited)