Improper surface preparation: If the wall is not clean and dry, the adhesive on the wallpaper may not adhere properly, causing it to not stick. Make sure to clean the walls with a mild detergent and let them dry completely before applying the wallpaper.

Incorrect installation: If the wallpaper is not applied correctly, such as not smoothing out bubbles or wrinkles, the adhesive may not make contact with the wall, causing it to not stick.

High humidity or moisture: If the wall or room has high humidity or moisture, it can cause the adhesive to lose its grip and the wallpaper not to stick.

Learn more in our blog: Common mistakes applying peel and stick wallpaper and how to fix them