1. The glue on the surface of the sticker is dry or aging. You can try to paste it again with new glue. Other glue has been used on the surface of the sticker, or you can try to apply new glue and stick it when it is dry.

2. If the surface of the sticker is not clean or has some impurities, it can be cleaned with detergent, dried and then pasted.

3. The surface of the sticker is too smooth or too cold. You can heat it with a hair dryer to make its surface slightly soft, and then paste it.

4. The sticker is damaged or cannot be pasted. You can try to change a new sticker.

5, the quality of the sticker is not good, you can try to buy a better quality crystal sticker.