Seems odd this happening. The Dynamax unit is a solid unit. I am wondering if the main aluminum mount might be cracked or something. There could very well be an issue with the motor, if it isn't in the mount. Do you have a different motor you could try?

For the blades to let go, they would have to hit something, and I sincerely doubt it is FOD. It takes a large hard object to do the damage you are stating here, liek putting a starter wand through at full throttle. I would guess the fan is hitting the shroud or, the mount is loose causing the fan to come back or twist and hit the stators. That would be where I would first start looking.