I got this one from Amazon, as the one provided with the Mini 4 was just too picky about positioning the props. It was more expensive than it should be for what is just a piece of moulded plastic, but it does the job well and still protects the props.
SKYREAT Mini 4 Pro Propeller Holder Strap,Mini 4 Propeller Guard Protector Stabilizer for DJI Mini 4 Pro Drone Propellers Props Blades Accessories https://amzn.eu/d/1Pr1rHz
@Shane22 Hi Shane, I wonder if you’re maybe not applying the DJI prop holder correctly. If it and the blades are positioned correctly it,'s easy to close and the blades should be able to move slightly… at least they do on my mini 4.
I agree, if you position it properly it will lock easily, there is a slight pressure on the props but it doesn’t look like it can cause any permanent damage.