I had the same problem on my 63100 freerchobby motors.
One had a moving axle resulting in a moving rotor. They sent me a new rotor (unbranded).
The other one was fine until I started to hear a “snap” sound everytime I brake or accelerate.
It was the axle that was moving… I put loctite 2 days ago on the grub screws, waited 24h and for now it works. But I didn’t ride a lot since, i hope it will last.
I used to have 63105 APS motors that were perfect for me, idk why I sold them
These freerchobby motors heat up like crazy comparing the APS. My wh/km increased a lot too (new motors + 3d servisas finality gear drive).
Do you think they can be poorly efficient ? Or it’s just normal for a closed can motor ?