The catches break. Its just a matter of time. Fortunately I had a spare from my last order. Ordered a couple more to have spares on hand because when they go, the door won't stay closed and the dryer stops working.
Last time, I took off the door and took the door apart to replace the catch. Unnecessary. I followed the video on your site this time and with the aid of a putty knife and some masking tape to protect the paint, I had the catch replaced in a couple minutes.