I just picked up two packs of replacement propellers from Amazon, OEM Dji plastic propellers, same model number, (DJI and 9450 on the propellers themselves) and they look exactly like the ones that came with the Phantom 3 Pro. However, while those spin on with little effort, these ones take a huge amount of force to get on. The grey ones are too tight to move at all, and the blacks are better, but still take much more effort then the stock ones. Amazon.com: 2 Pairs DJI Genuine Plastic 9450 Self-tightening Propellers for Phantom 3 OEM in New Clear Pack: Camera & Photo Has anyone else encountered this? I assume I just got a bad batch, and am returning, but all 8 of them had this issue.