Ring door sensors keep falling

I bought a couple of door sensors from Amazon. They keeping falling off. The sticky part stays but its the top part that keeps falling down, most often with the batteries coming out too. Are these faulty or am i missing something?

Hi @itsanil. For the Contact Sensor, you should be able to place the Contact Sensor over the mounting bracket, and slide it towards the edge (The side with the barcode). If the Contact Sensor is not on all the way, you will see a Tampered alert in your Ring App. If this continues to fall off, I would suggest reaching out to our Ring Alarm support team. Please give our support team a call at one of the numbers available here. If you are outside of the US, please visit here to see how to contact support.