Hi @Julian ,
Thank you for the detailed report. It does look like there is a missing (or broken? hard to see) magnet in the motor, in which case the motor will not work properly and should be replaced. No further testing is needed, as this is most likely a manufacturing defect of the motor or a result of an impact.
If you believe that the motor was defective when you received the product, you should request a free replacement motor (submit an RMA form) . If the motor was damaged while testing, you can purchase a new motor.
The Starling 2 Max replacement parts can be found here : https://www.modalai.com/products/starling-2-max-replacement-parts (however i don't see just motors without a frame + motors kit, will double check..)
Alex
