Kudos to Skyreat

[Lister]

My Min1 3 prop protector didn't close properly due to the strap being ever-so-slightly too short. I emailed them and they sent me a new one that does. Gotta love that degree of customer service.

 

[SpinItUp]

My Min1 3 prop protector didn't close properly due to the strap being ever-so-slightly too short. I emailed them and they sent me a new one that does. Gotta love that degree of customer service.

You need to close it from the side not strap it over straight, as if from the back.
Mine is exactly the same if it is done as I say it will stay closed

 

[SpinItUp]

Like this As if to push the button in from the side, not aimlessly straight over
Edit; just read the end of your sentence...it'll end up just the same