SmallRig 4122B Suction Cup Camera Mount (4")

I took a chance and purchased 2 of these suction cups to rig a mirrorless camera as securely as possible to a classic convertible, despite the lack of real world reviews. My plan was to use 2 of these, with a magic arm on each, attached to the top and bottom of the camera for stability. This rig didn't make it past testing it on my car before a shoot. Nothing fell off while I was driving - but 1 of the 2 of these suction cups kept losing suction after just a few minutes, no matter what I did, whether on windshields or even flat glass windows in my home. The button pops up quickly, exposing the white not enough suction indicator. The other suction cup of the 2 seems solid and reliable, though. I selected a small diameter (4) suction cup mount as I was unsure of the curvature of the windshield and wanted something that would be versatile but still have high enough rated strength to keep my camera safely in place. I wanted the mount to be able to stand up to some wind since it would be mounted in a convertible with the top down. With a dashboard camera inside a closed vehicle, you at least know that if the camera comes loose, it will likely fall into someone's lap - not nearly as dangerous to people or gear as if a camera were to fall OUT of a moving vehicle entirely. I can't risk using the defective one, especially in safety-critical mounting situations or even to mount a tube light to a window, etc. I'll be returning at least the defective one of the 2 I purchased for a replacement. If the problem persists, I'll have to send them both back and use only Cinemilled gear in the future...