1. Is the bracket flat on the instrument?

2. After fitting, is the base suction cup pressed to squeeze out the air?

3. Is the button pressed to lock it?

4. If it is not used properly and there is dust or other dirt on the adhesive after it falls off, the adhesive on our product is washable. Please wash the adhesive with water and let it dry. Then reinstall it again

And if you have completed the above four points but still cannot use it correctly, please contact us. We will guide you to operate and use. Thanks