1. Reduced market demand: After the blueberry mask has been sold in Wechat business channel for a period of time, the market demand may be reduced due to various reasons, such as poor product effect and decreased consumer interest.

2. Increased competitive pressure: With the passage of time, the competition in Wechat business has become more and more fierce, and various mask products have emerged one after another. Blueberry masks may be squeezed by other new products, resulting in a decline in their sales.

3. Change of agency system: The agency system in Wechat business may have changed, resulting in that the original agent no longer acts as an agent for blueberry mask, but a new agent or a direct manufacturer sells directly.

4. Product quality problems: If there are serious quality problems or negative news about blueberry mask, consumers may lose trust in the product, thus reducing their purchases.

5. Other reasons: For example, the internal changes of Wechat business's team, the changes of agent relationship or the adjustment of business strategy may cause Wechat business to stop making blueberry masks.

To sum up, there may be many reasons why Wechat business doesn't make blueberry masks, which need to be analyzed in detail.