Trouble with mamba maxx 5700 magnets ( I think)

G'Day I have posted this in the brushless forum but was advised to post it here.

I have a new mamba maxx 5700 motor that i have installed into a Traxxas Jato.
The motor sounded like it was cogging.
I took the pinion gear of the motor and the motor still sounded like it was cogging ( No gears connected, just motor sitting by itself)

I removed the back plate of the motor and took the shaft out.
What I have found is the magnet is in 3 pieces. This seams a bit odd.

Can I order new a new magnet for this motor? I take it that the magnet is a one piece or is it supose to be 3 seperate magnets?

Just trying to find out why it has a cogging sound and when I removed the shaft with the magnets, They came out as 3 pieces and look as if they have been broken.

I realise that now that i have taken it apart it won't be covered under waranty but as i am from Australia it would still cost a bit in freight.

Any information appreciated.