"Caking" or "clumping" of a product is common and is due to its natural amorphous sugar content. This occurs when the sugar crystals line up in the presence of moisture. Many powders are naturally susceptible to humidity, and they will absorb any moisture present in the air.
We are aware of this effect when packing products at our facility and have control measures in place to reduce the risk of this happening. However, fruit powders are particularly hygroscopic and tend to agglomerate due to being hydrophilic in nature, which can result in the powder clumping together.